2026.06.8., 22:10
Láng Attila D.
The BASIC Dictionary
2025
Private publication
© Láng Attila D., 2025
ISBN
Foreword
This book is a dictionary of the BASIC language, the programming language that played a crucial role in the spread of home computers in the 1970s and 1980s, and still today plays a role in computer programming.
The original BASIC language, developed by John G. Kemeny and Thomas E. Kurtz on Dartmouth College in 1965, was a product of its period. It lacked methods of structured programming, these being unknown yet, and didn’t know anything about graphics and sound, since they were using teletypes which were printing on paper instead of monitors.
Later, BASIC became more and more famous, and more and more manufacturers applied it in their computers. But since these machines were more advanced than the teletypes, and there were more advancements invented in programming, they needed to enhance the language. There was no standard for doing this, each developer chose their own methods. Compatibility was out of question yet. Therefore, BASIC got a lot of dialects that are very different, especially in certain areas like structured programming, graphics and sound handling. Actually, there are languages which can be considered BASIC dialects, but it’s ambiguous.
The aim of this dictionary is to collect as many dialects of BASIC as possible, and to present them in a comprehensive format that provides a good overview on the most important element of BASIC language: the keywords.
The Keywords
BASIC is organized around keywords. A BASIC program is built up from statements, and a statement always begins with a keyword (however, one of them regularly can be omitted, but implied). Some statements use more keywords.
Keywords are viewed by home computer programmers like Lego bricks for builders. Especially in the home computer world, programmers knew all keywords, including their syntaxes and all special tidbits of use, on their specific type of computer.
Therefore, this dictionary is based upon keywords. Each keyword has a dictionary entry, listing all the details known about that keyword in the BASIC dialects included.
BASIC Dialects Included
Commodore 64 (Microsoft BASIC 2.0)
Commodore Plus/4, 16, 116 (Microsoft BASIC 3.5)
Commodore 128 (Microsoft BASIC 7.0)
Enterprise
Simons’ BASIC
Sinclair ZX81
Sinclair ZX Spectrum
Computer Descriptions
Commodore 64
“The Commodore 64, also known as the C64, is an 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in the Guinness World Records as the highest-selling single computer model of all time, with independent estimates placing the number sold between 12.5 and 17 million units. Volume production started in early 1982, marketing in August for US$595 (equivalent to $1,880 in 2023). Preceded by the VIC-20 and Commodore PET, the C64 took its name from its 64 kilobytes (65,536 bytes) of RAM. With support for multicolor sprites and a custom chip for waveform generation, the C64 could create superior visuals and audio compared to systems without such custom hardware.” (Wikipedia)
The C64 isn’t featured for any keyword. I mean, there is no keyword tagged as C64, there are only ones tagged Commodore, Plus/4 and C128. Those listed as Commodore will work on the C64, but they will also work on later Commodore computers, the Plus/4 family and the C128, as well as on earlier Commodore computers like the PET and the VIC20.
Plus/4 and C128, however, received an extended version of C64’s simple BASIC dialect – too simple, in fact, since there is no BASIC support for many features of the computer.
Hardware
In the following, italics is used for features that cannot be reached from BASIC, only by memory manipulations.
64 KB memory, of which 38 is available for BASIC. 16 colors for all of the graphics detailed below.
Character screen: 25 rows, 40 characters. Redesignable characters. Multicolor character mode. Extended background mode.
High resolution graphics: 320 · 200 pixels with a foreground color changeable separately by character position (40 · 25 ones, 8 · 8 pixels each) and a single background color for the whole screen. Multicolor graphics: 160 · 200 pixels with two foreground and two background colors.
Sprite graphics: 8 sprites at the same time, each one set separately to 24 · 21 pixels (high resolution) or 12 · 21 pixels (multicolor). They can be shown single or double size in either or both horizontally or vertically. They can appear at any position of the screen, independent of its contents and mode (character screen, high resolution or multicolor graphics), including edge positions where they aren’t visible in whole.
Sound: 3 independent voices, 4 waveform for each. 3 amplitude modulators. 3 envelope generators with attack, decay, sustain and release values. Oscillator synchronization and ring modulation. Programmable filter. Volume setting.
Peripherals: keyboard (part of the computer), TV or monitor, cassette tape, floppy drive, printer, joystick, paddle and a lot more. Most important devices were manufactured by Commodore itself.
Commodore Plus/4, 16, 116
“The Commodore 16 is a home computer made by Commodore International with a 6502-compatible 7501 or 8501 CPU, released in 1984 and intended to be an entry-level computer to replace the VIC-20. A cost-reduced version, the Commodore 116, was mostly sold in Europe.
The C16 and C116 belong to the same family as the higher-end Plus/4 and are internally very similar to it (albeit with less RAM – 16 KB rather than 64 KB – and lacking the Plus/4’s user port and Three-Plus-One software). Software is generally compatible among all three provided it can fit within the C16’s smaller RAM and does not utilize the user port on the Plus/4.
While the C16 was a failure on the US market, it enjoyed some success in certain European countries and Mexico.” (Wikipedia)
This computer family is tagged as Plus/4 in the book. Keywords tagged as Commodore also work on them. Their BASIC 3.5 dialect is identical, an extended version of BASIC 2.0 of the C64. The only difference is the keyboard, and that Plus/ has got a built-in piece of software called Three-Plus-One, which has gained practically zero popularity.
Differences from C64:
121 colors instead of 8. (16 colors in 8 shades, but all shades of black are identical.)
Character screen: no multicolor or extended background mode.
Graphic screen: for both high resolution and multicolor, there is an additional mode when the bottom five rows of the character screen are visible at the bottom of the screen, covering the graphic screen.
Sprites don’t exist.
Sound: a much simpler sound chip which has 2 voices, of which one can emit white noise.
Unlike the C64, there are dedicated BASIC keywords for all graphic and sound features.
Commodore 128
“The C128 is a significantly expanded successor to the C64, with nearly full compatibility. It is housed in a redesigned case with an improved keyboard including a numeric keypad and function keys. Memory was enlarged to 128 KB of RAM in two 64 KB banks. A separate graphics chip provided 80-column color video output in addition to the original C64 modes. It also included a Zilog Z80 CPU which allows the C128 to run CP/M, as an alternative to the usual Commodore BASIC environment. The huge CP/M software library, coupled with the C64’s software library, gave the C128 one of the broadest ranges of available software among its competitors.” (Wikipedia)
The C128 can work in C64 mode when it is basically the same as the C64, or in C128 when it runs BASIC 7.0, a highly advanced BASIC dialect which includes all the keywords from BASIC 3.5 and additional ones for the greater hardware possibilities of the C64, which are all built in the C128, too. Keywords tagged as Commodore or Plus/4 also work on it.
Enterprise
“The Enterprise is a Zilog Z80-based home computer announced in 1983, but due to a series of delays, was not commercially available until 1985. It was developed by British company Intelligent Software and marketed by Enterprise Computers.
The specification as released was powerful and one of the higher end in its class (though not by the margin envisaged in 1983). This was due to the use of custom ASICs for graphics and sound which took workload away from the CPU, an extensive implementation of ANSI BASIC and a bank switching system to allow for larger amounts of RAM than the Z80 natively supported. It also featured a distinctive and colourful case design, and promise of multiple expansion options. Its two variants are the Enterprise 64, with 64 KB of RAM, and the Enterprise 128, with 128 KB of RAM.
The machine was renamed several times during development, being known variously as Samurai, Oscar and Elan. Versions can sometimes been found in magazine articles referred to by the preceding monikers. Ultimately, not assisted by release delays and a changing market place, the Enterprise was not commercially successful. The manufacturer called in the receivers in 1986 with significant debt, although old stock continued to be sold through a German partner until well into the 1990s.” (Wikipedia)
The Enterprise has an excellent BASIC, but it is almost forgotten. A greater fandom has been built in Hungary.
Simons’ BASIC
“Simons’ BASIC is an extension to BASIC 2.0 for the Commodore 64 home computer. Written by British programmer David Simons in 1983, who was 16 years old at the time, it was distributed by Commodore as a cartridge.” (Wikipedia)
This software adds many keywords to the aforementioned simple BASIC 2.0, including graphics, sound, structured programming, peripherals etc.
Sinclair ZX81
“The ZX81 is a home computer that was produced by Sinclair Research and manufactured in Dundee, Scotland, by Timex Corporation. It was launched in the United Kingdom in March 1981 as the successor to Sinclair’s ZX80 and designed to be a low-cost introduction to home computing for the general public.
[…]
The ZX81 was designed to be small, simple, and above all, inexpensive, with as few components as possible. Video output was designed for a television set rather than a dedicated monitor. Programs and data are loaded and saved onto compact audio cassettes. It uses only four silicon chips and 1 KB of memory.” (Wikipedia)
The ZX81 has got one of the most simple BASIC dialects. The tag Sinclair refers to both ZX81 and Spectrum.
Order of Precedence
( )
functions except NOT and unary –
**
unary –
* /
+ binary –
< = > <= >= <>
NOT
AND
OR
Limitations
Maximum line number allowed is 9999.
Each program line can contain only one statement. No : statement separator.
Numeric variables can have a name of any length.
String variables can have a single-letter name only, and a $ sign.
Arrays can have a single-letter name only, and a $ sign if string arrays.
An array cannot share its name with a scalar variable.
Loop variables used in FOR–NEXT can have a single-letter name only.
Numbers are stored to an accuracy of 9 or 10 digits.
Number precision is between 10³⁸ and 4*10⁻³⁹.
The screen has 24 lines with 32 character positions.
Program lines can be very long.
The contents of string variables can be very long.
Arguments of functions aren’t required to be enclosed in ( ) parentheses if the argument is one single literal or variable.
Sinclair ZX Spectrum
“The ZX Spectrum is an 8-bit home computer developed and marketed by Sinclair Research. One of the most influential computers ever made and one of the all-time bestselling British computers, over five million units were sold. It was released in the United Kingdom on 23 April 1982, and around the world in the following years, most notably in Europe and the United States.” (Wikipedia)
The younger brother of the ZX81, the Spectrum has got a simple, but relatively advanced BASIC dialect. The tag Sinclair refers to both ZX81 and Spectrum.
Order of Precedence
( )
functions except NOT and unary –
↑
unary –
* /
+ binary –
< = > <= >= <>
NOT
AND
Limitations
Maximum line number allowed is 9999.
Numeric variables can have a name of any length.
String variables can have a single-letter name only, and a $ sign.
Arrays can have a single-letter name only, and a $ sign if string arrays.
In variable names, spaces and control characters are ignored and all letters converted to lowercase.
Loop variables used in FOR–NEXT can have a single-letter name only.
Numbers are stored to an accuracy of 9 or 10 digits.
Number precision is between 10³⁸ and 4*10⁻³⁹.
The screen has 24 lines with 32 character positions.
Program lines can be very long.
The contents of string variables can be very long.
Arguments of functions aren’t required to be enclosed in ( ) parentheses if the argument is one single literal or variable.
Concepts in Programming
(to be written:) dummy, expression, file, function, light pen, logical file number, paddle, peripheral, subroutine, type (variable)
array
A collection of values (numbers or strings), having a common name and a unique index for each one. An array can be one-dimensional: a series; two-dimensional: a table; three-dimensional: values arranged in a cube; and more. In BASIC, an array must be either numeric or string type, but not both.
argument
A numeric or string value a function can work with, specified after the name of the function. All BASIC functions have syntax rules telling how many arguments can they take and what can they be.
ASCII
American Standard Code for Information Interchange. A code table created in the 1960s to encode characters with numbers. Originally, ASCII was having 128 code points, numbered from 0 to 127; later this was extended till 255. Since this is the largest number that can be stored in a single byte, ASCII could not be extended further. Being this not enough, they invented Unicode.
auxiliary keyword
A keyword that plays some modifying role in a statement which was defined by another keyword. At other places, an auxiliary keyword may be a statement or function keyword, in the same dialect or in other dialects.
beam
On the Enterprise, this is the name of the graphic cursor.
binary numbers
A numbering system when each digit has a place value twice the one standing at its right. So, 1 means one, 10 means two, 100 means four and 1000 means eight. This system has only two digits, 0 and 1, which also correspond to false and true, respectively.
binary operator
An operator that stands between two operands and acts on them. (The term has nothing to do with binary numbers.) For example, in 2 + 2, the symbol + is a binary operator.
bit
The smallest unit of information. A bit can store a value of 0 or 1. 8 bits are collected together to a byte.
bitwise operation
An operation on numeric values that concerns to their bit representation. For example, logically, 3 AND 8 is true (–1 or 1, depending on the dialect) because both 3 and 8 are nonzero values. But bitwise, 3 AND 8 is 0, because the binary representation for 3 is 0011, the one for 8 is 1000, so there’s no bit which would be 1 for both.
byte
The smallest unit of memory directly accessible. A byte contains 8 bits and thus it can store an integer value from 0 to 255.
carriage return
A special control character (decimal 13 in ASCII) which used to be sent to teletype machines to mean “return the carriage”, i.e. send the printing head to the beginning of the line. After this, a line feed (LF) was sent. After the age of teletypes, many computers were using the CR only, but Windows is still using both (CR/LF), and Unix is using LF only.
cartridge
A small electronic device consisting of a circuit in a plastic casing. Some home computers had a connector reserved for a cartridge. Cartridges can contain software (for example, a single game) or add advanced functionality.
cassette tape recorder
Or magnetophone, a simple electronic device in general use from the 1960s for storing music. Most home computers applied the same cassettes and same recorders as household music recordings.
character
An entity encoded by a special table (the ASCII table) to serve as part of strings. On home computers, every character is encoded with one byte, thus there may be 256 different characters existing at the same time. With Unicode, more bytes are used for a character, so the system can display a much greater variety of them.
Types of characters include printable and non-printable characters. Printable characters are letters, digits, punctuation and special symbols, and graphic characters. Non-printable characters are control characters which, when printed, change something on the screen, e.g. clear it, switch to a different color, move the cursor etc.
On ZX81 and Spectrum, all keywords are treated as single characters and typed with one single keypress (plus one or two modifier keys).
On most computers, the shape of printable characters can be redesigned. The computer won’t notice the change (for instance, a keyword PRINT is still the same keyword even if you redraw all the five letters to different shapes, since it operates on codes, not shapes).
character screen
A screen mode when only characters can be displayed. There is an invisible grid on the screen, dividing it to a certain number of lines and to a certain number of character positions; both numbers are specific to each computer. In each character position, exactly one character may be displayed because there is a single byte of the memory assigned to each one, and if the contents of a byte is changed, the character will change, too. Since on home computers, characters are encoded with one byte, only 256 different characters may appear on the screen. If you redesign any character, all instances of it will change immediately.
Many home computers have no graphic screen, only a character screen. Others have both, in different modes. Spectrum has no character screen, only a graphic screen.
command
Similar to the statement, but isn’t part of a BASIC program. In dialects using line numbers, a command is entered without a line number, that’s how the interpreter knows it is a command. Some keywords can be used only in command mode, others only in statement mode, and most of them in both modes.
compatible
Two computers are compatible if both can run the same programs. A peripheral is compatible with a computer if it can work with it.
compiler
A program created to make the computer to understand BASIC language. All keywords and their syntaxes were defined when the creator wrote the compiler. A compiler differs from an interpreter in its working mode: the compiler reads the complete BASIC code and translates it to machine code. Execution can take place only after this. Compiling takes time, but furthermore, the compiler isn’t necessary to run the program. BASIC compilers rarely appeared for home computers, they were mostly using interpreters.
concatenation
Appending a string to another one. For example, by concatenating strings "BA" and "SIC" you will get "BASIC". In BASIC, the concatenation is marked by the + symbol, the same one as for numeric addition.
constant
A value that cannot be changed in the run of the program. Constants are both literal constants which are written directly in the program, and named constants which are created similar to a variable, but their values cannot be changed later. Most home computer BASIC dialects don’t know named constants.
CR
Carriage return.
cursor
A marker on the screen which shows where will the next character be displayed. On different computers, it could be a flashing or non-flashing square, a horizontal line or a vertical line. When the computer is working on its own and we aren’t typing, the cursor is usually not visible, but it is there.
On Sinclair, the cursor is an inverted letter which show what mode is the keyboard in. Depending on the mode, the same key types different characters.
decimal numbers
The numbering system we are using in everyday life. Here, 10 means ten (ten times one), 100 means a hundred (a hundred times one) and so on. In programming, other systems are frequently used: hexadecimal, binary and sometimes octal, too.
degrees
The best known way to measure angles, used in everyday life. A right angle is 90 degrees, a complete circle is 360 degrees. Computers often use radians instead.
device
Enterprise uses several channels to communicate with devices. Channels are numbered 0 to 254, while devices have names. Default channels are:
0 – command input and normal text output, connected to device "EDITOR:", itself using devices "KEYBOARD:" and "VIDEO:".
1 to 100 – available for the user.
Channels 101 to 105 are automatically open until explicitly closed.
101 – graphics input and output.
102 – standard text page.
103 – standard sound output, connected to device "SOUND:".
104 – connected to device "PRINTER:".
105 – connected to device "KEYBOARD:".
106 – file-based input and output. Connected to device "DISK–1:" if available; if not, connected to device "TAPE:". Additional disk drives are "DISK–2:" and so on. Additional tape drives are similarly numbered.
107 – for network operations. Device "NET–0:" is the general channel, for broadcasting for all machines and for receiving data without specifying the source machine. Devices "NET–1:" to "NET–32:" are for specific machines. "SERIAL:" is a serial port.
device number
Commodore
There is a number to identify which peripheral do you want to communicate with. These are used in the OPEN statement:
0 = keyboard
1 = cassette tape; secondary address: 0 = input, 1 = output, 2 = output, writing an end of tape mark after CLOSE
2 = modem
3 = screen
4 and 5 = printer; secondary address: 0 = uppercase/graphic characters, 1 = lowercase/uppercase characters
8 to 11 = floppy drive; secondary address: 0 = save, 1 = load, 2 to 14 = data channels, 15 = command channel
dialect
BASIC is a programming language which is distributed by many companies for many computers. Based on both the different abilities of different computers and the personal taste of manufacturers, they can be very different: both the set of available keywords and their syntaxes may differ. Additionally, there are extensions for some dialects which add or modify keywords, thus are considered separate dialects.
dummy
A meaningless parameter or argument, required only by syntax but not used.
execution
When a program is running, its statements are executed one after another, as determined by the structure of the program.
expression
One or more values (literals and/or variables), connected by operators, forming a mathematical formula or a string processing formula.
floppy disk
A mass storage media largely used in the 1980s and 1990s. A floppy (flexible) plastic circle with a magnetic layer, enclosed in a square plastic envelope.
floppy drive
A device used for reading and writing floppy disks. Among them, a special category is the Commodore floppy drives which are programmable computers with an own language.
graphic cursor
An invisible cursor for the graphic screen which points to a pixel where the next graphic operation will draw to if no coordinates are given.
graphic screen
A screen mode where graphic shapes can be displayed. For home computers, graphic screens were memory consuming and slow, but the only way to freely (or relatively freely) draw on the screen. The graphic abilities of these computers were very diverse, and seen by our time, very low-key: low resolution, few colors.
Many home computers have no graphic screen at all. On the other hand, the Spectrum has only a graphic screen.
hard disk, hard drive
The most frequent mass storage device of our time. But for home computers, it was barely known and almost never used. Most home computers used cassette tape recorders and some of them floppy disks, too.
hexadecimal numbers
A numbering system frequently used in programming; actually, it’s a shorthand for binary numbers, used for better reading by humans. The system uses 16 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A (=10), B (=11), C (=12), D (=13), E (=14) and F (=15). Each digit has 16 times the place value than the one standing at its right: 10 means sixteen, 100 means two hundred and fifty-six, and 1000 means four thousand and ninety-six.
home computer
A category of computers being marketed from the end of the 1970s to the end of the 1980s. Relatively cheap, small computers with less knowledge than personal computers. Most of them had a small memory (those times, that was the most expensive part), a smaller selection of compatible peripherals, most of them used an household television instead of a monitor, and a household cassette tape recorder instead of a floppy drive or hard drive.
integer
A number with no fractional part (like 8). In most BASIC dialects, there are integer variables for storing only these numbers.
integer variable
A variable which can store only integer numbers. Storing a fractional value like 1.2 in an integer variable will result in 1, truncating the fractional part. In most BASIC dialects, these wear a % percent symbol as a suffix to their names. There are dialects which don’t know this type.
interpreter
A program created to make the computer to understand BASIC language. All keywords and their syntaxes were defined when the creator wrote the interpreter. An interpreter differs from a compiler in its working mode: the interpreter reads a statement, understands and executes it, then goes on to the next statement. Home computer BASIC dialects are written as interpreters.
inverse
Displaying characters a different way: the characters are shown in the color of the screen background, while the little squares encompassing each (see character screen) are colored to the character color. On many home computers, it’s the only method to add characters some emphasis.
keyword
A basic element in BASIC. A keyword is a single word (in this dictionary, some symbols are also treated as keywords). Its spelling is fixed and cannot be changed. Traditionally, keywords are written in ALL CAPS; the oldest computers didn’t have lowercase letters at all. On Sinclair computers, all keywords are treated like single characters (which appear as several characters, but each one encoded in one byte). Keywords identify statements, commands, functions, operators and others. Different BASIC dialects may use the same keyword for different purposes, or may use different keywords for the same purpose. Each keyword has one or more syntaxes, which also can be different in different BASIC dialects.
LF
Line feed.
line feed
A special control character (decimal 10 in ASCII) which used to be sent to teletype machines to mean “line feed”, i.e. to rotate the paper feeding cylinder one row further. This was sent after a carriage return. After the age of teletypes, many computers were using the CR only, but Windows is still using both (CR/LF), and Unix is using LF only.
line number
In older BASIC dialects, all lines of a program must begin with a number. This is both to separate them from commands (which have no number and are executed immediately) and to specify the order of execution. Traditionally, we are using numbers increasing by 10 (10, 20, 30 etc.), to make it easier to insert additional lines later.
literal
A numeric or string value directly written in a program line. Numeric literals are simply numbers. String literals are strings enclosed in " quotation marks.
logical value
A value that can either be true or false, nothing else. In BASIC, a numeric value of 0 represents false, and any non-zero value corresponds to true. If a logical operation returns a value of true, it is represented by –1 in most dialects, but in some dialects, 1.
logical operation
An operation on logical values. In most BASIC dialects, AND, NOT and OR are the available operations, but these keywords are often working as bitwise operations. In some dialects, also the XOR operation is available.
machine code
The native tongue of the processor. Not discussed in books dealing with BASIC language, since it’s a different language, but in some dialects, there are tools for working with machine code.
mass storage
A device that can store large amounts of information, in a way that it won’t be forgot upon switching the device off (what was a great problem with memories in 20th century computers). Mass storage devices are using some kind of data carrier media to write the actual data on. The earliest one was the punch card, then the punched tape (both made of paper and working with holes punched on them). Then came several kinds of plastic with a magnetic layer: the drum memory, the floppy disk and the hard disk. Later, the optical disks appeared, but the hard disks are still the most important mass storage media.
memory
An electronic device that can store information. Computers need memory to work. Since for a long period, memories were very expensive and forgot everything upon switching off, different types of mass storage were used.
modifier keyword
A Spectrum specialty. BRIGHT, FLASH, INK, INVERSE, OVER and PAPER can stand as statements on their own, thus affecting all subsequent graphic statements. Or they can appear inside graphic statements, even more of them in the same statement, thus affecting only that statement. Graphic statements that can be altered this way include CIRCLE, DRAW, INPUT, PLOT and PRINT.
name
In programming, we often need names. Variables, files, procedures (in some dialects), and other things are always reached by names. The names are chosen by the programmer. Each dialect has its own rules for what do they accept as a name. The most frequent rule is that a name must contain only letters and digits, and must begin with a letter.
numeric variable
A variable storing a number. In most BASIC dialects, numeric variables wear no symbol as a suffix to their names. Many dialects provide integer variables which can’t hold a fractional number, these have a suffix % (percent mark). Some dialects feature additional numeric variables, too.
octal numbers
A numbering system used in programming in the early period; later, it was replaced by hexadecimal numbers. Actually, a shorthand for binary numbers. The system uses only 8 digits, from 0 to 7. 10 means eight and 100 means sixty-four.
operand
A value (literal, variable or expression) that an operator is acting on.
operator
A symbol that can be used in expressions to act on values (literals, variables or partial expressions). These include fundamental arithmetic operations like + and –, and others. BASIC has a lot less operators than mathematics.
option
An Enterprise specialty: a keyword representing a setting in the operating system and acting like a system variable. In this dictionary, option syntaxes are shown with the SET statement, or ASK when SET is not applicable.
order of precedence
When evaluating expressions, all BASIC dialects have a certain order of precedence between operators, similar to mathematics. Those listed first will be processed first (e.g. multiplication before addition). Operators of the same rank will be processed left to right.
parameter
A numeric or string value a statement can work with, specified after the name of the statement. All BASIC statements have syntax rules telling how many parameters can they take and what can they be.
peripheral
A device connected to the computer and serving for some purpose. There are input peripherals: keyboards, mice, joysticks, scanners etc.; output peripherals: monitors (TV), printers, audio devices.
personal computer
A category of computers marketed since the 1980s. Most computers used nowadays are personal computers.
pixel
The smallest unit of graphics that can be painted. The number of available pixels is called the graphic resolution and depends on the type of computer and the mode of graphic screen currently in effect.
program
A list of statements to be processed in order when needed. Programs can be very simple and minimal or large and complex.
program line
A line of text written on a computer, in a programming environment, according to the rules of some programming language (in this book: the BASIC language). In older versions of BASIC, program lines always began with a number which determined the order of execution, and served as reference for statements that acted on some program lines. Newer version omit line numbers, they’re using modern text editors instead, and the order of execution is simply determined by the physical order of the lines in the text.
radians
A way to measure angles, often used by computers. A full circle is 2π radians.
reserved variable
A variable which is reserved by BASIC for some special purpose. May be thought about as a function with no argument.
scalar variable
A non-array variable, which can contain only one numeric or string value at a time.
sprite
On C64 and C128, a sprite is a graphic shape which can appear independently to the contents of the screen. It works on both the character screen and the graphic screen. Its design is drawn by the programmer in two or four colors and it can move freely around. 8 sprites can be used.
statement
A basic element in BASIC. A statement can do some interaction with the screen, the keyboard or some peripheral; can make calculations using previously computed values; can change the order of processing program lines; can make decisions; and more. Each statement begins with a BASIC keyword (one of them can be omitted) which tells BASIC what to do and may contain parameters which tell BASIC how to do it. A statement is always part of a BASIC program, in a program line beginning with a line number (in those dialects that require line numbers). Most statements can appear with no line number as commands.
string
A series of characters kept together in a specified order. Literal strings are directly written in the program, enclosed in " quotation marks. Strings can be stored in string variables, too. The shortest string is the empty string: two quotation marks "" directly following each other, with nothing in between. The longest string allowed depends on the dialect.
string function
A function that operates on one or more strings. In a broader sense, any function that either or both takes a string as input or gives one as output is a string function. The narrower sense covers only those that give string output. These ones are wearing a $ dollar symbol as a suffix to their names.
string variable
A variable storing a string value. In most BASIC dialects, string variables wear a $ dollar symbol as a suffix to their names, and they’re strictly separated from numbers.
syntax
The grammar of BASIC language and of a given keyword. Programming languages, including BASIC, are a lot simpler than languages spoken by humans. They have only a few keywords, and each one has a syntax (or more syntaxes) which tells how does the interpreter understands them. The syntax must be followed rigorously, otherwise we will get an error message.
teletype
A machine looking like an electric typewriter: what you type was immediately appearing on paper. From the 1950s, they were used as the main I/O peripheral for computers: the user typed on the teletype which both printed on the paper and sent the messages to the computer, and it printed the answers on the paper, too. Screens (televisions, monitors) weren’t be used yet. That’s why displaying characters on the screen is still called printing. The teletypes disappeared in the 1970s.
UDG
Short for User Defined Graphics. A Spectrum specialty. There are 20 characters in the Spectrum character set which are easily redefinable.
unary operator
An operator that acts on a single operand. There are prefixed and postfixed unary operators, but most dialects of BASIC have only two unary operators, the – for negative numbers, and NOT.
Unicode
The character encoding standard used nowadays. It can support millions of different characters. But home computers didn’t know it, they only knew ASCII.
variable
A storage area in the memory of the computer, marked by a name and serving to hold some information. There are numeric and string variables, scalar variables and arrays.
ASCII Tables
Commodore
The Commodore machines discussed in this book are using almost the same code tables. There are two, the ASCII table (in the modern literature: PETSCII) and the POKE code table. The ASCII table is used by ASC and CHR$, and internally for all character operations. It contains control characters, too. The POKE code table is used for storing information in the screen memory, and several screen related Simons statements are using it, too. It doesn’t contain control characters. When redesigning character shapes, we have to refer to the POKE code table.
Commodore ASCII Table
Where there are two characters listed, the left one is the uppercase/graphics character set, the right one is the lowercase/uppercase one. Where there is one character, it is the same for both.
ASCII codes are in decimal.
The structure of the codes:
0 to 31 – control characters
32 to 127 – printable characters
128 to 159 – control characters
160 to 255 – printable characters
0 to 1 unused
2 underline on (only on C128, 80 columns mode)
3 STOP
5 white
6 unused
7 bell (only on C128)
8 disable character set change; on C128: unused
9 enable character set change; on C128: TAB
10 only on C128: line feed
11 only on C128: enable character set change
12 only on C128: disable character set change
13 RETURN
14 lowercase/uppercase character set
15 on C128: flash on
16 unused
17 cursor down
18 reverse on
19 HOME
20 DEL
21 to 23 unused
24 only on C128: tab set/clear
25 to 26 unused
27 ESC (unused on Commodore 64)
28 red
29 cursor right
30 green
31 blue
32 space
33 !
34 "
35 #
36 $
37 %
38 &
39 .
40 (
41 )
42 *
43 +
44 ,
45 -
46 '
47 /
48 0
49 1
50 2
51 3
52 4
53 5
54 6
55 7
56 8
57 9
58 :
59 ;
60 <
61 =
62 >
63 ?
64 @
65 A
66 B
67 C
68 D
69 E
70 F
71 G
72 H
73 I
74 J
75 K
76 L
77 M
78 N
79 O
80 P
81 Q
82 R
83 S
84 T
85 U
86 V
87 W
88 X
89 Y
90 Z
91 [
92 £
93 ]
94 ^
95 ←
128 unused
129 orange; on C128: dark purple
130 on Plus/4: flash on; on C128: underline off
131 RUN
132 on Plus/4: flash off
133 F1
134 F3
135 F5
136 F7
137 F2
138 F4
139 F6
140 F8; on Plus/4: HELP
141 SHIFT+RETURN
142 uppercase/graphics character set
143 on C128: flash off
144 black
145 cursor up
146 reverse off
147 CLEAR
148 INST
149 brown; on C128, 80 columns mode: dark yellow
150 pink; on Plus/4: yellow-green
151 dark gray; on Plus/4: pink; on C128, 80 columns mode: dark cyan
152 medium gray; on Plus/4: blue-green
153 light green; on Plus/4: light blue
154 light blue; on Plus/4: dark blue
155 light gray; on Plus/4: light green
156 purple
157 cursor left
158 yellow
159 cyan
Color Tables
Commodore 64 and Commodore 128, 40 columns mode
1 = black
2 = white
3 = red
4 = cyan
5 = purple
6 = green
7 = blue
8 = yellow
9 = orange
10 = brown
11 = light red
12 = dark grey
13 = medium grey
14 = light green
15 = light blue
16 = light grey
Plus/4
All statements related to color handling use a colortype parameter, which can be one of the following:
0 = background color
1 = foreground color (on the graphic screen, it can be different in each character cell)
2 = multicolor 2 (on multicolor graphic screen only, can be different in each character cell)
3 = multicolor 3 (on multicolor graphic screen only, uniform on the whole screen)
4 = border (only in the COLOR statement)
C128
The colortype parameter is a little changed from the Plus/4:
0 = 40 column background
1 = 40 column foreground
2 = multicolor 1
3 = multicolor 2
4 = 40 column border
5 = 40 or 80 column characters
6 = 80 column background
In 80 column mode, the colors are:
1 = black
2 = white
3 = dark red
4 = light cyan
5 = light purple
6 = dark green
7 = dark blue
8 = light yellow
9 = dark purple
10 = dark yellow
11 = light red
12 = dark cyan
13 = medium grey
14 = light green
15 = light blue
16 = light grey
The Dictionary
ABS
function
all
ABS(x)
Returns the absolute value of x. The absolute value is the same value for non-negative numbers, and the appropriate positive value for negative ones.
ACCESS
auxiliary
Enterprise
An auxiliary keyword for OPEN.
ACOS
function
Enterprise
ACOS(x)
Returns the arc cosine of x
ACS
function
Sinclair
ACS x
Returns the arc sine of x. On ZX81, it appears as ARCCOS on the keyboard, but on the screen, it is ACS.
ALL
auxiliary
Enterprise
An auxiliary keyword for SAVE.
ALLOCATE
statement
Enterprise
ALLOCATE bytes
Reserves the given number of bytes for a machine code routine. Erases all variables.
AND
operator
all
x AND y
Returns the bitwise AND value of the operands.
ANGL
statement
Simons
ANGL x, y, angle, xr, yr, dmode
Draws a ray of a circle or ellipse. dmode in high resolution: 0 = erasing, 1 = drawing, 2 = inverting; in multicolor: 1–3 = the colors specified in MULTI and LOW COL statements, 4 = inverting (colors 3–0 instead of 0–3).
ANGLE
function
Enterprise
ANGLE(x, y)
The angle between the positive x-axis and the line between points 0, 0 to x, y.
APPEND
statement
C128
APPEND#lf, file$[, Ddev] [{ON|,} Uunit]
Opens a file$ to append, placing the pointer at the end of it.
ARC
statement
Simons
ARC x, y, begin, end, step, xr, yr, dmode
Draws an arc of a circle or ellipse from angle begin to end, in steps of step degrees. dmode: see ANGL.
ASC
function
all, except Sinclair and Enterprise
ASC(a$)
Returns the ASCII code of the first character of a$, according to the ASCII table of the given computer. Same as CODE.
ASK
statement
Enterprise
ASK {option|n} var
Puts the value of option to variable var. Specifying a number n instead will reach an operating system variable.
ASN
function
Sinclair
ASN x
Return the arc sine of x. On ZX81, it appears as ARCSIN on the keyboard, but on the screen, it is ASN. Same as ASIN.
ASIN
function
Enterprise
ASIN(x)
Returns the arc sine of x. Same as ASN.
AT
special_function auxiliary
Sinclair
AT row, column
Places the cursor at the given position of the screen. Can be used only in the PRINT and LPRINT statements; in the latter, the row number is ignored.
ZX81
row must be between 0 and 21, column must be between 0 and 31.
Simons
AT(column, row)
Enterprise
An auxiliary keyword for AUTO, DISPLAY, INPUT, LOOK and RENUMBER.
ATN
function
all
ATN(x)
Returns the arc tangent of x radians.
On ZX81, it appears as ARCTAN on the keyboard, but on the screen, it is ATN.
ATTR
function
Spectrum
ATTR(row, column)
Returns the attributes from the character position specified. It is a single byte, with bits meaning: 7 = FLASH, 6 = BRIGHT, 5–3 = PAPER, 2–0 = INK.
ATTRIBUTE
auxiliary
Enterprise
An auxiliary keyword for GRAPHICS.
ATTRIBUTES
option
Enterprise
SET ATTRIBUTES a
Sets a control flag in attribute video mode. a = 1 plotting in paper color, 2 without affecting bitmap data, 4 without affecting ink attributes, 8 without affecting paper attributes, 16, 32, 64 and 128 are the same as above but with printing.
AUTO
command
Plus/4
AUTO [step]
Turns automatic line numbering on (if step is present) or off (if step is omitted). When it’s on, entering a BASIC program line and pressing RETURN yields the next line number, the previous one plus step, be displayed.
Simons
AUTO first, step
first is the first number to be used.
Enterprise
AUTO [AT first] [STEP step]
Default first is 100, step is 10. Automatic numbering can be stopped by pressing STOP.
B
auxiliary symbol
C128
Auxiliary keyword for BLOAD, BSAVE.
Simons
A bit marking symbol for the @ statement.
BACKUP
statement
Plus/4
BACKUP Ddeva TO Ddevb [{ON|,} Uunit]
Copies a floppy disk from device deva to device devb on dual floppy drive unit. Cannot be used on single floppy drives.
BANK
statement
C128
BANK bank
Activates the selected memory configuration. bank means:
0–3 RAM only, 0 to 3
4–7 internal ROM with RAM 0 to 3
8–11 external ROM with RAM 0 to 3
12 kernal and internal ROM, RAM 0
13 kernal and external ROM, RAM 0
14 kernal and BASIC ROM, RAM 0, character ROM
15 kernal and BASIC ROM, RAM 0
BCKGNDS
statement
Simons
BCKGNDS gr, a, b, c
Switches to extended background color mode. gr is the background color, a, b and c are the background colors for Shifted, inverted and inverted Shifted characters, respectively.
BEAM
option
Enterprise
SET [£chan:] BEAM {ON|OFF}
When the beam is moved, it will leave a line behind it if it’s ON.
BEEP
statement
Spectrum
BEEP length, pitch
Sounds a note for length seconds at a pitch pitch semitones above (or below if it’s negative) the middle c.
BEGIN
statement
C128
BEGIN
Allows several lines to be included in an IF–THEN–ELSE structure:
IF condition THEN BEGIN: statement
…
… BEND: ELSE BEGIN
…
… BEND
BEND
statement
C128
BEND
Closes a BEGIN clause (see there).
BFLASH
statement
Simons
BFLASH speed[, a, b]
Starts flashing the border between colors a and b, with speed 1 = slowest, 255 = fastest, or 0 = turns it off (then colors aren’t needed).
BIAS
option
Enterprise
SET [£chan:] BIAS c
Establishes which group of colors will figure as numbers 8–15 within the palette. c is the standard code number of any color within the group, 0 to 31, or an RGB function. The bias is applied to every palette.
BIN
special_function function
Spectrum
BIN number
Allows numbers to be entered in binary. number can be a binary constant only. Largest number allowed is 16 digits (1111111111111111 = decimal 65535).
Enterprise
BIN(number)
BLACK
reserved_constant
Enterprise
BLACK
The color black = RGB(0, 0, 0).
BLOAD
statement
C128
BLOAD file$[, Ddev][, Uunit][, Bbank][, Paddr]
Loads a binary file to the memory in the given bank, from the address addr.
BLOCK
statement
Simons
BLOCK x1, y1, x2, y2, dmode
Draws a filled rectangle. dmode: see ANGL.
BLUE
reserved_constant
Enterprise
BLUE
The color blue = RGB(0, 0, 1).
BOOT
statement
C128
BOOT file$[, Ddev][{ON|,} Uunit]
Loads and executes a binary file.
BORDER
statement option
Spectrum
BORDER c
Sets the color of the border, and also the paper color of the lower part of the screen (where BASIC lines are entered).
Enterprise
SET [£chan:] BORDER c
BOX
statement
Plus/4
BOX [colortype], x1, y1, x2, y2[, angle[, fill]]
Draws a rectangle with colortype from x1, y1 to x2, y2. It is rotated by angle radians. If fill is 1, it is filled.
BRIGHT
statement modifier
Spectrum
BRIGHT b
Sets the brightness for graphic statements. b 0 = normal, 1 = bright, 8 = transparent. Can be used as a statement or a modifier for graphic statements.
BSAVE
statement
C128
BSAVE file$[, Ddev][, Uunit][, Bbank], Paddr TO Pend
Saves a binary file from the memory in the given bank, from the address addr to address end.
BUMP
function
C128
BUMP(n)
Returns a byte containing the numbers of sprites that collided since the previous BUMP. n 1 = sprites collided with each other, 2 = sprites collided with the contents of the screen. The returned value is 1 on each bit (sprites 0 to 7).
C
symbol
Simons
A bit marking symbol for the @ statement.
CALL
statement
Simons
CALL label
Jumps to the line marked with PROC label. Can’t be followed by another statement in the same line.
Enterprise
CALL function[(parameters)]
Calls a built-in or user DEFined function. Any result is ignored.
CAPTURE
statement
Enterprise
CAPTURE FROM £ch1 TO £ch2
Captures input from channel ch1 and substitutes it for input expected from channel ch2.
CAT
statement
Spectrum
CAT …NO INFO
Accesses the catalog of the microdrive. Details unknown.
CATALOG
statement
C128
CATALOG [Ddev][{ON|,} Uunit][, joker$]
Same as DIRECTORY.
CAUSE
statement
Enterprise
CAUSE [EXCEPTION] ex
Causes an error by error code ex. The keyword EXCEPTION is optional.
CEIL
function
Enterprise
CEIL(x)
Gives the smallest whole number not less than x, so, rounds it up to the nearest whole number.
CENTRE
statement
Simons
CENTRE a$
Prints a$ centered in the line.
CGOTO
statement
Simons
CGOTO x
Calculated GOTO where x can be an expression.
CHAIN
statement
Enterprise
CHAIN {programnumber|programname (parameters)}
Executes another program, called by programnumber or programname, giving parameters to it.
CHAR
statement
Plus/4
CHAR [colortype], x, y[, a$[, invert]]
Prints a$ at position x, y (character coordinates) on either the character screen or the graphic screen, whichever is currently on. If invert is 1, it appears inverted.
Simons
CHAR x, y, code, dmode, size
Prints the character of POKE-code code on the graphic screen in size size. dmode: see ANGL.
CHARACTER
option
Enterprise
SET [£chan:] CHARACTER n, a, b, c, d, e, f, g, h, i
Defines the pattern of the character with ASCII code n, with numbers a to i defining each row of pixels as a byte. The change will affect all video pages. To return all characters to their default settings, use CLEAR FONT.
CHECK
function
Simons
CHECK({a, b|0})
If two numbers are given, it returns 0 if two sprites collided. If 0 is given, it returns 0 if a sprite collided with screen contents.
CHR$
function
all
CHR$(x)
Returns the character belonging to the ASCII code x,cording to the ASCII table of the given computer. x must be between 0 to 255, inclusively.
CIRCLE
statement
Plus/4
CIRCLE [colortype], [x, y], xr, [yr], [start], [end], [rot], [angle]
Draws a circle or ellipse with colortype, centered at x, y or at the graphic cursor if coordinates are omitted. xr and yr are the axis lengths. start and end are the two endpoints of an arc to be drawn. rot is the rotation. angle is the angle between two points being drawn: if it is 120, we get a triangle. (All angles are degrees.)
Spectrum
CIRCLE x, y, r
Draws a circle with radius r.
Simons
CIRCLE x, y, xr, yr, dmode
dmode: see ANGL.
CLEAR
statement
Sinclair
CLEAR
Clears all variables from the memory. Same as CLR.
Enterprise
CLEAR {£chan:|ENVELOPE|FKEYS|FONT|GRAPHICS|NET|QUEUE soundsource|SCREEN|SOUND|TEXT}
Clears or restores various options. CLEAR FKEYS restores function key definitions. CLEAR FONT default character shapes. CLEAR GRAPHICS clears the graphic screen, CLEAR TEXT the text screen, CLEAR SCREEN any screen. CLEAR ENVELOPE clears the sound envelope, CLEAR SOUND the sound, CLEAR QUEUE the specified soundsource. CLEAR NET the network. CLEAR £chan: clears a channel.
CLOSE
statement
Commodore
CLOSE lf
Closes the file or peripheral opened by the logical file number lf.
Enterprise
CLOSE £chan
Closes the channel, flushing and freeing the buffers.
CLOSE#
statement
Spectrum
CLOSE# …NO INFO
Closes a file on the microdrive. Details unknown.
CLR
statement auxiliary
Commodore
CLR
Clears all variables from the memory. Same as CLEAR. On Plus/4 and C128, also an auxiliary keyword for GRAPHIC.
CLS
statement
Sinclair
CLS
Clears the screen. Same as SCNCLR.
CMD
statement
Commodore
CMD lf[, message$]
Redirects all subsequent PRINT statements to the file or peripheral opened by logical file number lf. If message$ is present, it will be printed there.
CMOB
statement
Simons
CMOB b, d
For the statement @, defines the colors for the points marked B and D, respectively.
CODE
statement function auxiliary
Sinclair
CODE a$
Returns the ASCII code of the first character of a$, according to the ASCII table of the given computer. Same as ASC.
Also an auxiliary keyword for SAVE.
Enterprise
CODE [var]=string
Copies a string, assumed to contain machine code, to the position indicated by the current location counter. var can later be used to call the routine.
COLD
command
Simons
COLD
Restarts Simons’ BASIC.
COLLECT
statement
Plus/4
COLLECT [Ddev][{ON|,} Uunit]
Reorganizes the blocks on the floppy in device dev on unit unit.
COLLISION
statement
C128
COLLISION type[, line]
Turns on (if line is missing, turns off) the sprite collision interrupt. When it’s on, and a sprite collides, a GOSUB line is executed. type is 0 = sprite to sprite collision, 1 = sprite to background collision.
COLOR
statement
Plus/4
COLOR colortype, color[, luminosity]
Assigns colortype to the specified color and luminosity.
Enterprise
Keywords COLOR and COLOUR can be changed interchangeably. See details under COLOUR, CURSOR COLOUR and VIDEO COLOUR.
COLOUR
statement option
Simons
COLOUR border, background
Sets the border and background color.
Enterprise
SET [£chan:] COLOUR p, c
Sets the value of a color in the palette. p is the palette number, 0 to 7. c is the color code 0 to 255 or an RGB function. Keyword COLOR can be used instead of COLOUR.
CONCAT
statement
C128
CONCAT second$[, Ddeva] TO first$[, Devb][{ON|,} Uunit]
Appends file second$ to the end of file first$.
CONT
command
Commodore|ZX81
CONT
Continues the running program, after an error, a STOP statement or a user break. Same as CONTINUE.
CONTINUE
statement
Spectrum|Enterprise
CONTINUE
Continues the running program, after an error, a STOP statement or a user break. Same as CONT.
On the keyboard, it’s spelled CONT, but on the screen, it is CONTINUE.
COPY
statement
Plus/4
COPY [Ddeva,] [filea] TO [Ddevb,] [fileb] [{ON|,} Uunit]
Copies file filea to file fileb between devices deva and devb on unit unit. If filea is missing, all files are copied.
Sinclair
COPY
Makes a copy of the screen to the printer.
Simons
COPY
Makes a copy of the graphic screen to the printer.
Enterprise
COPY FROM £ch1 TO £ch2
Copies the contents of channel ch1 to channel ch2.
COS
function
all
COS(x)
Returns the cosine of x radians.
COSH
function
Enterprise
COS(x)
Returns the hyperbolic cosine of x.
COT
function
Enterprise
COT(x)
Returns the cotangent of x.
CSC
function
Enterprise
CSC(x)
Returns the cosecant of x.
CSET
statement
Simons
CSET x
x 0 = switch to uppercase mode, 1 = switch to lowercase mode, 2 = switch to the graphic screen used last.
CURSOR CHARACTER
option
Enterprise
SET [£chan:] CURSOR CHARACTER code
Specifies the ASCII code for a character to be used for the cursor.
CURSOR COLOUR
option
Enterprise
SET [£chan:] CURSOR COLOUR p
Specifies the palette number p to be used for the cursor. Keyword COLOR can be used instead of COLOUR.
CYAN
reserved_constant
Enterprise
CYAN
The color cyan = RGB(0, 1, 1).
D
auxiliary
Plus/4
Auxiliary keyword for APPEND, BACKUP, BLOAD, BOOT, BSAVE, CATALOG, COLLECT, CONCAT, COPY, DCLEAR, DIRECTORY, DLOAD, DOPEN, DVERIFY, HEADER, RENAME and SCRATCH.
DATA
statement auxiliary
all, except ZX81
DATA constant[, …]
Serves as a storage place of data which can be read later into variables. constants can be both numeric or string types, but when reading them, we must avoid trying to read a string data to a numeric variable, this would give an error.
String constants don’t need to be included in " quotation marks, except those that contain a , comma.
On Spectrum, also an auxiliary keyword for LOAD and SAVE.
DATE
statement
Enterprise
DATE date$
Sets the current date for the internal clock. date$ is in the format yyyymmdd.
DATE$
function
Enterprise
DATE$
Returns the current date in the format yyyymmdd.
DCLEAR
statement
C128
DCLEAR [Ddev][{ON|,} Uunit]
Closes all files and open channels on the drive.
DCLOSE
statement
C128
DCLOSE[#lf][{ON|,} Uunit]
Closes the file with logical file number lf, or all open files if it’s omitted, on the disk.
DEC
function
Plus/4
DEC(a$)
Converts a hexadecimal number between 0 and FFFF to decimal.
DEF
statement
Commodore
DEF FN name(variable)=expression
Defines a user function. The function can later be called as FNname(x) and will calculate the value of the expression with variable replaced by x. It is a symbolic argument. The argument, and therefore also x, must be numeric.
Spectrum
DEF FN name([variable[, …])=expression
The name and all variables are single-letter ones. DEF FN is a single keyword.
Enterprise
DEF name[(variable[, …])[=expression]
If =expression is present, it’s a single line function definition like on the previous systems. If it’s missing, calling the function name executes all subsequent lines till an END DEF line. Assigning a value to name will return the value from the function.
Functions can be called by CALL or as normal functions.
DEFAULT CHANNEL
option
Enterprise
SET DEFAULT CHANNEL chan
Specifies the channel to communicate with the user. Default value is 0.
DEG
function
Enterprise
DEG(x)
Returns x radians in degrees.
DEGREES
auxiliary
Enterprise
An auxiliary keyword for OPTION ANGLE.
DELAY
statement auxiliary
Simons
DELAY n
Sets the speed for the LIST command: n 1 = fastest, 255 = slowest.
Enterprise
An auxiliary keyword for WAIT.
DELETE
command
Plus/4
DELETE lines
Deletes lines from the program. For valid syntaxes, see LIST.
Enterprise
DELETE {lines|block}
Same as on Plus/4, with the following additions: FIRST and LAST can be used to refer to the first or last line of the program, respectively; and instead of lines, a block can be specified, referring to a function definition DEFined by the given block name. In lines, the – symbol can be replaced by TO.
Spectrum
DELETE …NO INFO
Deletes something on the microdrive. Details unknown.
DESIGN
statement
Simons
DESIGN mode, addr
Starts designing something, depending on mode: 0 = a hires sprite, 1 = a multicolor sprite, 2 = a character. For a sprite, it should be followed by 21 @ statements; for a character, by 8.
DETECT
statement
Simons
DETECT n
Turns sprite collision detection on. n 0 = with each other, 1 = with the screen contents.
DIM
statement
all (exceptions below)
DIM variable(dimension[, …])[, …]
Declares an array. It may be of any variable type. dimensions are one or more numbers defining the highest available index of that dimension (maximum allowed is 32767); the lowest index is 0. Several arrays can be declared in a DIM statement. If an array is used with no declaration, it’s automatically dimensioned name(10).
Sinclair
The lowest index is 1, and the last dimension of a string array is the length of the strings. So, DIM a$(10, 10) declares an array of 10 strings that are 10 characters long. Arrays cannot be used with no declaration.
Enterprise
Only one or two dimensions are allowed. By DIM name(lowest TO highest), the lowest and highest indexes can be specified.
DIR
statement
Simons
DIR a$
Lists the directory of the disk, those files that match a$.
DIRECTORY
statement
Plus/4
DIRECTORY [Ddev] [{ON|,} Uunit][, a$]
Lists the directory of the files on the disk in device dev on unit unit. If a$ is present, only the files matching it will be listed.
DISABLE
statement
Simons
DISABLE
Switches ON KEY off.
DISAPA
statement
Simons
DISAPA
Used as first statement on the line, marks it for encrypting with SECURE.
DISK
statement
Simons
DISK a$
Sends a$ as a command to the floppy drive.
DISPLAY
statement
Simons
DISPLAY
Lists the strings assigned to the function keys.
Enterprise
DISPLAY £chan: AT a FROM b TO c
Defines a window to display a segment of a text or graphics video page. a is the screen row where the top line of the segment will be placed. b and c are character rows on the page to be displayed.
DISPLAY GRAPHICS
statement
Enterprise
DISPLAY GRAPHICS
Switches to graphic screen mode.
DISPLAY TEXT
statement
Enterprise
DISPLAY TEXT
Switches to character screen mode.
DIV
function
Simons
DIV(x, y)
Integer division.
DLOAD
statement
Plus/4
DLOAD a$ [Ddev][{ON|,} Uunit]
Loads a file named a$ from the disk in device dev on unit unit.
DO
statement
Plus/4|Enterprise
DO [{UNTIL|WHILE} x]
Begins a loop. If either UNTIL or WHILE is present, x is evaluated. If UNTIL is present, the loop will end when x is true. If WHILE is present, the loop will end when x is false. If neither one is present, the ending condition will be evaluated by the LOOP statement. If neither DO nor LOOP contains an ending condition, the loop can be quit only by a statement EXIT (on Plus/4) or EXIT DO (on Enterprise) or by stopping the program.
DOPEN
statement
C128
DOPEN#lf, file$[, Llength][, Ddev][{ON|,} Uunit][, write]
Opens a file on the disk. If file$ ends in: ,S = sequential file, ,P = program file. length is the record length for relative files. If write is true, it will opened for writing, otherwise for reading. If logical file number lf is bigger than 127, all writes will be automatically ended with a CR/LF. Below 128, only a CR will be sent.
DOWNB
statement
Simons
DOWNB r1, c1, r2, c2
Scrolls a rectangle of the character screen down. On the top, empty space comes in.
DOWNW
statement
Simons
DOWNW r1, c1, r2, c2
Scrolls a rectangle of the character screen down. On the top, the contents scrolled out come in.
DRAW
statement
Plus/4
DRAW [colortype], [x1, y1] [TO x2, y2 …]
Draws a line or a series of lines. x1 and y1 are the coordinates of the starting point, or if this is omitted, the graphic cursor will be used. The TO part can be repeated several times, resulting in a series of lines.
Spectrum
DRAW x, y, r
Draws a line from the graphic cursor to x, y while turning in angle r.
Simons
DRAW a$, x, y, dmode
Draws a shape. a$ describes the shape by these characters: 0 = moving right, 1 = up, 2 = down, 3 = left, 5–8 = the same with drawing, 9 = end of drawing
DS
reserved_variable
Plus/4
DS
Returns the error code of the floppy drive.
DS$
reserved_variable
Plus/4
DS$
Returns the error message of the floppy drive.
DSAVE
statement
Plus/4
DSAVE a$ [Ddev] [{ON|,} Uunit]
Saves a file named a$ on the disk in the device dev on unit unit.
DUMP
statement
Simons
DUMP
Prints the values of all scalar variables.
DUP
function
Simons
DUP(a$, n)
Returns a string containing a$, n times.
DURATION
auxiliary
Enterprise
An auxiliary keyword used for SOUND.
DVERIFY
statement
C128
DVERIFY file$[, Ddev][{ON|,} Uunit]
Compares the file$ with the program being in the memory.
EDIT
command
Enterprise
EDIT {programnumber|programname}
Chooses the active program to be used.
EDITOR BUFFER
option
Enterprise
SET EDITOR BUFFER n
Defines the size of the editor buffer as n*256 byte chunks, for editor channels subsequently opened.
EDITOR KEY
option
Enterprise
SET EDITOR KEY chan
Allows channel chan to be used as the editor’s keyboard input.
EDITOR VIDEO
option
Enterprise
SET EDITOR VIDEO chan
Allows channel chan to be used as the editor’s text page.
EL
reserved_variable
Plus/4
EL
Returns the number of the line the recent error occurred in. Same as ERRLN.
ELSE
auxiliary
Plus/4|Simons
Auxiliary keyword for IF and RCOMP.
END
statement
all, except Sinclair
END
Finishes the program.
END DEF
statement
Enterprise
END DEF
Finishes a DEF function.
END HANDLER
statement
Enterprise
END HANDLER
Finishes a HANDLER handler.
END IF
statement
Enterprise
END IF
Finishes an IF branch.
END LOOP
statement
Simons
END LOOP
Closes a LOOP loop.
END PROC
statement
Simons
END PROC
Closes a PROC procedure.
END SELECT
statement
Enterprise
END SELECT
Finishes a SELECT branch.
END WHEN
statement
Enterprise
END WHEN
Finishes a WHEN block.
ENVELOPE
statement auxiliary
Simons
ENVELOPE voice, a, d, s, r
Sets the envelope for voice (1–3) with attack, decay, sustain and release.
Enterprise
ENVELOPE £chan: NUMBER a; b, c, d, e; f, g, h, i; …; [RELEASE; j, k, l, m; …]
a identifies the envelope. For the first phase, b is the change of pitch in semitones, c and d are the change in volume for the left and right speakers, respectively (0 to 63, in proportion of the overall maximum volume set in the SOUND statement, or –63 turns the sound off), and e is the duration of the phase in 1/50 seconds. f to i are the second phase, and so on. The RELEASE part defines phases performed after the conclusion of the previous phases or at the expiry of the SOUND duration if there is no following sound on the same channel.
It’s also an auxiliary keyword for SOUND.
EPS
function
Enterprise
EPS(x)
The smallest quantity that can be added to or subtracted from x to make the computer register a change in the value of x.
ER
reserved_variable
Plus/4
ER
Returns the code of the recent error. Same as ERRN.
ERASE
statement
Spectrum
ERASE …NO INFO
Deletes something on the microdrive. Details unknown.
ERR$
function
Plus/4
ERR$(x)
Returns the error message belonging to error code x.
ERRLN
reserved_variable
Simons
ERRLN
Returns the number of the line the recent error occurred in. Same as EL and EXLINE.
ERRN
reserved_variable
Simons
ERRN
Returns the number of the line the recent error occurred in. Same as ER.
EXCEPTION
auxiliary
Enterprise
An auxiliary keyword for CAUSE.
EXEC
statement
Simons
EXEC label
Calls a PROC procedure. Can’t be followed by another statement in the same line.
EXIT
statement
Plus/4
EXIT
Leaves a DO–LOOP loop.
EXIT DEF
statement
Enterprise
EXIT DEF
Leaves a DEF–END DEF loop
EXIT DO
statement auxiliary
Enterprise
EXIT DO
Leaves a DO–LOOP loop. Also can be an auxiliary keyword for READ.
EXIT FOR
statement
Enterprise
EXIT FOR
Leave a FOR–NEXT loop.
EXIT HANDLER
statement
Enterprise
EXIT HANDLER
Breaks out of an exception handler, which propagates the exception to the surrounding environment. This will cause another exception handler to be activated, either a user handler or the default handler.
EXIT IF
statement
Simons
EXIT IF condition
IF condition is true, exits the LOOP–END LOOP loop.
EXLINE
function
Enterprise
EXLINE
Returns the number of the statement that caused an exception.
EXOR
function
Simons
EXOR(x, y)
Bitwise EXOR operation.
EXP
function
all
EXP(x)
Returns e = 2.7182818…, the base of the natural logarithm on the power of x.
EXSTRING$
function
Enterprise
EXSTRING$(e)
Returns the error message belonging to exception e.
EXT
statement
Enterprise
[EXT |:]command
Sends a command to the operating system. If symbol : is used, no " quotation marks are needed around the command.
EXTYPE
function
Enterprise
EXTYPE
Returns the category number of the last exception.
FAST
statement
ZX81|C128
FAST
Turns the screen off to make the program run faster. Only the SLOW or NEW statement, an error or the end of the program will turn it on again.
FAST SAVE
option
Enterprise
SET FAST SAVE {ON|OFF}
Sets the saving speed for tape. Fast speed is about 2400 baud, the default. Slow speed is 1200.
FCHR
statement
Simons
FCHR row, column, width, height, code
Fills the selected area of the screen with the character of the specified POKE code.
FCOL
statement
Simons
FCOL row, column, width, height, color
Fills the selected area of the character screen with the specified character color. The characters won’t change.
FETCH
statement
Simons
FETCH mark, n, a$
An alternative INPUT statement which accepts up to n characters in a$. mark controls the accepted character set: HOME = only unshifted letters, CRSR ↓ = only digits, CRSR → = letters, digits and punctuation.
C128
FETCH bytes, inaddr, bank, exaddr
Takes bytes bytes from the external memory, from the specified bank and address exaddr, and stores them in the internal memory from address inaddr.
FILL
statement
Simons
FILL row, column, width, height, code, color
Fills the selected area of the character screen with both the character of the POKE code and color.
FILTER
statement
C128
FILTER freq, l, b, h, res
Sets audio filtering parameters. freq is the cut-off frequency (0 to 2047), l, b and h are the low-pass, band-pass and high-pass filters, respectively (0 = of, 1 =on), and res is the resonance, 0 to 15.
FIND
statement
Simons
FINDanything
Lists the numbers of program lines where anything is found. If a space is included before anything it will be part of the search.
FIRST
auxiliary
Enterprise
An auxiliary keyword for DELETE, LIST, LLIST and RENUMBER.
FKEY
option
Enterprise
SET [£chan:] FKEY n a$
Sets function key n to produce a$ each time it is pressed. Keys 1 to 8 are unshifted function keys, 9 to 16 are shifted ones. To return all function keys to default settings, use CLEAR FKEYS.
FLASH
statement modifier
Spectrum
FLASH f
Sets the flashing for graphic statements. f 0 = normal, 1 = flash, 8 = no change. Can be used as a statement or a modifier for graphic statements.
Simons
FLASH color, speed
Makes the color flash on the character screen: 1 is slowest, 255 is fastest.
FLUSH
statement
Enterprise
FLUSH £chan
Flushes the buffer of channel chan without closing it or signalling end of file.
FN
function
Commodore
FNname(x)
Returns the value of the user function name with argument x. User functions are defined with DEF FN.
Spectrum
The arguments must be enclosed in ( ) parentheses; even if no argument the parentheses must be there.
FOR
statement
all
FOR variable=start TO end [STEP step]
Begins a loop when it counts from start to end (by 1 or step if specified), and the actual count is always in variable. It must be numeric. The end of the loop is the NEXT statement.
FORMAT
statement
Spectrum
FORMAT …NO INFO
Formats the microdrive. Details unknown.
FP
function
Enterprise
FP(x)
Returns the fractional part of x. Same as FRAC.
FRAC
function
Simons
FRAC(x)
Returns the fractional part of x.
FRE
function
Commodore
FRE(dummy)
Returns the amount of free memory in bytes.
FREE
function
Enterprise
FREE
The amount of free memory available to the current program.
FROM
auxiliary
Enterprise
An auxiliary keyword for CAPTURE, COPY, DISPLAY and REDIRECT.
GET
statement
Commodore
GET[#lf, ]variable$[, …]
Reads a keypress. If no key is pressed, returns an empty string. If #lf is present, reads a character from the file opened by logical file number lf. See also GETKEY and INKEY$.
Enterprise
GET £chan: variable$
Defaults to the keyboard.
GETKEY
statement
Plus/4
GETKEY a$
Waits until a key is pressed, and returns it in a$. If a numeric variable is specified, the statement will accept a digit only, otherwise it throws an error.
GLOBAL
statement
Simons
GLOBAL
Makes all LOCAL variables global.
GO
statement
Commodore
GO TO line
The GO keyword serves only to make it possible to write keyword GOTO in two words, using the TO keyword.
Beyond the definition above, on C128, the statement GO64 switches the computer to Commodore 64 mode, and performs a reset. If used as a command, a message Are you sure? will appear, and a Y keypress will make the switching. If used in a program, the message won’t appear.
GOSUB
statement
all
GOSUB line
Redirects execution to a subroutine at the program line line. It must be a numeric constant. Later, a RETURN statement will take back to the recently executed GOSUB statement.
On Sinclair, the keyword is written GO SUB and line can be an expression.
GOTO
statement
all
GOTO line
Redirects execution to the program line line. It must be numeric constant. On Commodore systems, the keyword can be written in two words: GO TO.
On Sinclair, the keyword is written GO TO and line can be an expression.
GRAPHIC
statement
Plus/4
GRAPHIC {mode[, clear]|CLR}
Sets the mode of the screen. If clear is 1, the screen is cleared.
Available screen modes:
0 = text mode
1 = high resolution graphic
2 = high resolution graphic, split screen
3 = multicolor graphic
4 = multicolor graphic, split screen
In split screen modes, the bottom of the screen displays five lines of the text screen, but above it, the graphic screen is visible.
GRAPHIC CLR frees the memory occupied by the graphic screen.
C128
Same as in Plus/4 but there is an additional mode: 5 = 80 column text.
GRAPHICS
statement
Enterprise
GRAPHICS [{{HIRES|LORES} [colors]|ATTRIBUTE}]
Sets a graphic screen mode. With no parameters, it closes and reopens the default graphics and text pages, then displays the default graphics page with 4 lines of text at the bottom. HIRES and LORES sets the high or low resolution, respectively, with the specified number of colors or with the previous value if omitted; values available are 2, 4, 16 and 256. ATTRIBUTE selects the attribute mode when each 8·1 pixel area can contain two colors.
GREEN
reserved_constant
Enterprise
GREEN
The color green = RGB(0, 1, 0).
GSHAPE
statement
Plus/4
GSHAPE a$[, [x, y][, mode]
Puts the shape stored in a$ on the screen; the shape was stored earlier by SSHAPE. x and y are the coordinates of the top left corner; if they’re omitted, the graphic cursor is used. mode can be one of the following:
0 = overwrites the earlier contents (default)
1 = inverse display
2 = in OR relation to the contents
3 = in AND relation to the contents
4 = in XOR relation to the contents
HANDLER
statement
Enterprise
HANDLER name
Defines a block of statements which deal with errors. An END HANDLER statement marks its end.
HEADER
statement
Plus/4
HEADER a$, Ddev[, Iid [{ON|,} Uunit]
Formats a floppy disk in device dev on unit unit, assigning it a name a$ and an ID number id. If Iid is omitted, the disk won’t be formatted but only erased. For new, unformatted disks, this cannot be used.
HELP
command
Plus/4
HELP
After an error, lists the line where the error was found, with the part causing the error marked. Plus/4: flashing; C128, 40 column mode: inverse; C128, 80 column mode: underlined.
HEX$
function
Plus/4
HEX$(x)
Returns the hexadecimal value of x, which can be between 0 and 65535.
Enterprise
HEX$(x$)
Returns a string of bytes given the hex values of the bytes in x$ which lists comma-separated values written in two-digit hex codes, case-insensitive.
HI COL
statement
Simons
HI COL
Restores the colors as they were before the LOW COL statement.
HIRES
statement auxiliary
Simons
HIRES ink, paper
Switches to high resolution screen and sets colors.
Enterprise
An auxiliary keyword for GRAPHICS.
HRDCPY
statement
Simons
HRDCPY
Prints the character screen on the printer.
I
auxiliary
Plus/4
Auxiliary keyword for HEADER.
IF
statement
all (exceptions below)
IF expression {THEN {statements|line}|GOTO line}
Evaluates expression. If the result is non-zero, executes the statements to the end of the line, or if GOTO line or THEN line is used, redirects execution.
Plus/4 Simons
IF expression {THEN {statements|line}|GOTO line}[: ELSE {statements|line}]
An ELSE clause can be added. These statements will be executed if the result is false.
C128
See also BEGIN and BEND.
ZX81
IF expression THEN statement
IF MISSING
auxiliary
Enterprise
An auxiliary keyword for INPUT and READ.
IMAGE
statement
Enterprise
IMAGE: format
Like PRINT USING on some systems, it defines the format of output for the PRINT statement. Everything after the symbol : to the end of line is part of the format, which can contain the following characters: for numeric values: , a , comma, $ a floating $ sign, – a floating space or – sign, + a floating + or – sign, % a digit or a leading zero, £ a digit or space, trailing zeros after a decimal point, * a digit or leading *, . a decimal point, ^ (minimum 4) the exponent part; for string values: < left justification (must start the field), > right justification, £ a character.
IN
function
Spectrum
IN port
Reads a value from a processor port which must be between 0 and 65535.
Enterprise
IN(port)
INF
reserved_constant
Enterprise
INF
The largest positive number the computer can handle = 9.999999999*10^62.
INFO
statement
Enterprise
INFO
Gives a printout of the system memory and available memory, and a listing of programs with their sizes and first lines. Clears all variables.
INK
statement modifier option
Spectrum
INK i
Sets the ink color of graphic statements. i 0–7 = a color, 8 = transparent, 9 = contrast. Can be used as a statement or a modifier for graphic statements.
Enterprise
SET [£chan:] INK i
i is a palette number except in 256 colors mode when it is a standard color code.
INKEY
function
Simons
INKEY
Waits for a function key to be pressed and returns its number.
INKEY$
function
Sinclair Enterprise
INKEY$
Reads a keypress. If no key is pressed, returns an empty string. See also GET.
INPUT
statement
all (exceptions below)
INPUT [message;] variable[, …]
If message (a string constant) is present, displays it. Displays a ? question mark, then waits for keyboard input. As many variables are provided in the statement, so many values are expected, separated by , commas, of the same type as required by the statement.
ZX81
INPUT variable
Spectrum
INPUT [[(]message[)];] [LINE] variable
The message can contain everything allowed in PRINT. If there is any variable in message, the complete prompt must be in ( ) parentheses. If variable is a string variable, a pair of " quotation marks appear in the left part of the screen, unless LINE is specified before variable, which must be a string variable in this case.
Enterprise
INPUT £chan [IF MISSING action,] [AT row, column,] [PROMPT prompt:] variable[, …]
Reads variables from channel chan. prompt replaces the default ? prompt. action is executed when there is no value (see READ). AT puts the prompt to the specified row and column. IF MISSING and PROMPT may be in either order.
INPUT#
statement
Commodore
INPUT#lf, variable[, …]
Like INPUT but reads the values from the file opened with the logical file number lf.
INSERT
function
Simons
INSERT(needle, haystack, offset)
Returns haystack, inserting needle in it at the offsetth character, before the rest of haystack.
INST
function
Simons
INST(needle, haystack, offset)
Returns haystack, inserting needle in it at the offsetth character, overwriting the rest of haystack.
INSTR
function
Plus/4
INSTR(haystack$, needle$[, offset])
Searches for the first occurrence of needle$ in haystack$ from offset and returns the character offset, or 0 if not found.
INT
function
all
INT(x)
Returns the integer part of x. This is the biggest integer which is smaller than x. Thus, INT(1.5) = 1 but INT(–1.5) = –2.
INTERRUPT
auxiliary
Enterprise
An auxiliary keyword used for SOUND.
INTERRUPT CODE
option
Enterprise
ASK INTERRUPT CODE var
Asks the software interrupt code for the last interrupt.
INTERRUPT KEY
option
Enterprise
SET INTERRUPT KEY {ON|OFF}
When ON, causes a software interrupt for any keypress.
INTERRUPT NET
option
Enterprise
SET INTERRUPT NET {ON|OFF}
Turns on or off the software interrupt caused by receiving data from the network.
INTERRUPT STOP
option
Enterprise
SET INTERRUPT STOP {ON|OFF}
Turns on or off the software interrupt from the STOP key.
INV
statement
Simons
INV row, column, width, height
Inverts the selected part of the character screen.
INVERSE
statement modifier
Spectrum
INVERSE i
Sets the true or inverse video for graphic statements. i 0 = true video, 1 = inverse video. Can be used as a statement or a modifier for graphic statements.
IP
function
Enterprise
IP(x)
Returns the integer part of x, the decimal part chopped off.
JOY
function
Plus/4
JOY(x)
Returns the status of the joystick x where x can be 1 or 2. The values are:
0 = no movement
1 = forward
2 = forward right
3 = right
4 = right backward
5 = backward
6 = backward left
7 = left
8 = left forward
128 is added if the fire button is pressed.
Simons
JOY
The values returned are the same as on Plus/4.
Enterprise
JOY(n)
n is the number of the joystick, 0 is the built-in one, 1 and 2 are additional ones. Values returned:
1 = right
2 = left
4 = down
8 = up
16 = fire button (for the built-in joystick, it’s the space key)
KEY
statement
Plus/4
KEY [n, a$]
Assigns the string a$ to the function key n (1 to 8; the HELP key is the 8th). If no parameter is given, lists the assignments.
Simons
The statement is written the same as on Plus/4. But the key assignment is different, because the computers themselves are numbering them differently.
KEY CLICK
option
Enterprise
SET KEY CLICK {ON|OFF}
Sets the click for keypresses on or off.
KEY DELAY
option
Enterprise
SET KEY DELAY t
Sets the keyboard delay before auto-repeat starts to t/50 second.
KEY RATE
option
Enterprise
SET KEY RATE t
Sets the keyboard auto-repeat rate to t/50 seconds.
L
auxiliary
Plus/4
Auxiliary keyword for DOPEN.
LAST
auxiliary
Enterprise
An auxiliary keyword for DELETE, LIST, LLIST and RENUMBER.
LBOUND
function
Enterprise
LBOUND(array[, dim])
Returns the lower bound of the array in the dimth dimension or in the only one if dim is omitted.
LCASE$
function
Enterprise
LCASE$(s$)
Returns s$ converted to lowercase characters.
u🟩LEFT
auxiliary
Enterprise
An auxiliary keyword used for SOUND.
LEFT$
function
all, except Sinclair
LEFT$(a$, x)
Returns x characters from the left side, i.e. from the beginning of a$.
LEFTB
statement
Simons
LEFTB r1, c1, r2, c2
Scrolls a rectangle of the character screen left. From the right, empty space comes in.
LEFTW
statement
Simons
LEFTW r1, c1, r2, c2
Scrolls a rectangle of the character screen left. From the right, the contents scrolled out come in.
LEN
function
all
LEN(a$)
Returns the length (the number of characters) of a$.
LET
statement
all (exceptions below)
[LET] variable=value
Stores the value in variable. They must be of the same type.
In most BASIC dialects, the keyword LET can be omitted. A statement which doesn’t begin with a keyword is considered a LET statement.
Sinclair
The keyword LET mustn’t be omitted. A variable mustn’t be referred to before giving it a value with a LET statement or, for an array, before declaring it in a DIM statement.
Substrings (see the keyword entry for ( ) parentheses) can stand at the left side of the = symbol. This makes only a portion of the string to be changed. If the assigned string is longer than the substring range specified, its end will be truncated. If it is shorter, it will be filled at the end with spaces. Characters beyond the substring range won’t change.
Enterprise
[LET] variable[, …]=value
Several variables (including array elements) can be specified and all will receive the same value. The keyword LET must be written only if a variable’s name is a keyword.
LINE
statement auxiliary
Simons
LINE x1, y1, x2, y2, dmode
Draws a line. dmode: see ANGL.
Spectrum
An auxiliary keyword for INPUT and SAVE.
LINE INPUT
statement
Enterprise
LINE INPUT £chan [IF MISSING action,] [AT row, column,] [PROMPT prompt:] variable[, …]
Details see at INPUT (section Enterprise). Reads a whole line, including commas etc. for each variable. Only string variables are allowed.
LINE MODE
option
Enterprise
SET [£chan:] LINE MODE m
Determines the way colors of the existing display and newly plotted lines interact. m = 0 overwrites anything plotted before, 1 means an OR relation, 2 AND relation, 3 XOR relation.
LINE STYLE
option
Enterprise
SET [£chan:] LINE STYLE s
Sets line style to s = 1 to 14 which means various types of broken lines.
LIST
command
all (exceptions below)
LIST [lines]
Lists the lines of the program. If lines are specified, only a part of the list is shown. Possible ranges:
first
first–
–last
first–last
ZX81
LIST [line]
Only one number can be given, and it lists a screenful of the program from that line. Also, it makes the line the current line (the one marked for editing).
Enterprise
LIST [£chan:][{lines|blockname}]
See DELETE for details.
LLIST
statement
Sinclair
LLIST [line]
Lists the lines of the program on the printer. If line is specified, the listing begins from that line.
Enterprise
LLIST [£chan:][{lines|blockname}]
See LLIST for details.
LN
function
Sinclair
LN x
Returns the natural logarithm of x. Same as LOG.
LOAD
command
Commodore
LOAD [filename$[, device]]
Loads a program from the specified device. If filename$ is specified (not an empty string), the program with the appropriate name will be searched. Otherwise, the first one is loaded.
Sinclair
LOAD filename$
Spectrum
LOAD filename DATA [$]()
Loads an array from the filename. If the $ symbol is present, it is a string array; without it, a numeric array.
LOAD filename CODE [addr[, len]]
Loads the file into the memory from address addr, at most len bytes if it’s specified. If addr is missing, it is loaded to the address it was saved from.
LOAD f SCREEN$
Loads the contents of the screen.
Enterprise
LOAD [{[£chan:]filename|devicename}]
If no channel is specified, loads from cassette, or disk if attached. With no parameter, it loads the first file. See OPEN for devicename. The loaded program replaces the current one in memory. If multiple BASIC programs have been saved as one file, these will replace all programs in memory.
LOCAL
statement
Simons
LOCAL variable[, …]
Makes the listed variables local for a part of the program; they must be defined earlier.
LOCATE
statement
Plus/4
LOCATE x, y
Puts the graphic cursor to the given location. The contents of the screen won’t change.
LOG
function
all
LOG(x)
Returns the natural logarithm of x. Same as LN.
LOG10
function
all
LOG10(x)
Returns the base 10 logarithm of x.
LOG2
function
all
LOG2(x)
Returns the base 2 logarithm of x.
LOOK
statement
Enterprise
LOOK [£chan] [AT x, y:] v
On the page chan or on the standard graphics page, looks at point x, y or if this is missing, the point at the graphic cursor, and puts the palette color found there to v. If AT is present, it moves the graphic cursor to x, y.
LOOP
statement
Plus/4|Enterprise
LOOP [{UNTIL|WHILE} x]
Closes a loop, started by a DO statement. If either UNTIL or WHILE is present, x is evaluated. If UNTIL is present, the loop will end when x is true. If WHILE is present, the loop will end when x is false. If neither one is present, the ending condition will be evaluated by the DO statement.
Simons
LOOP
Marks the beginning of a LOOP–END LOOP loop.
LORES
auxiliary
Enterprise
An auxiliary keyword for GRAPHICS.
LOW COL
statement
Simons
LOW COL a, b, c
In multicolor graphics, sets three alternative colors.
LPRINT
statement
Sinclair|Enterprise
LPRINT [element][separator][…]
Works the same as PRINT but for the printer. AT works the same way as TAB.
LTRIM$
function
Enterprise
LTRIM$(s$)
Removes all spaces from the beginning of s$.
MAGENTA
reserved_constant
Enterprise
MAGENTA
The color magenta = RGB(1, 0, 1).
MAX
function
Enterprise
MAX(a, b)
Returns the bigger number of a and b.
MAXLEN
function
Enterprise
MAXLEN(s$)
Gives the maximum length specified for s$.
MEM
statement
Simons
MEM
Copies the character memory from the ROM to the RAM, to make it redefinable.
MERGE
statement
Spectrum
MERGE filename$
Loads the filename$ but doesn’t delete the old am nor its variables. Both were present at the same time. Lines with the same number will replace old lines; variables with the same name will replaces old variables.
Simons
MERGE filename$, device
The same as on Spectrum but requires a device number to load it from.
Enterprise
MERGE £chan:filename
Only in immediate mode. Clears variables.
MID$
function
all, except Sinclair
MID$(a$, from, count)
Returns a part of a$ from the character number from (the first character is numbered 1) in the length of count characters.
On Commodore, it can be a statement:
MID$(a$, from, count)=b$
This replaces the given portion of a$ with b$. Here, a$ must be a variable.
MIN
function
Enterprise
MIN(a, b)
Returns the smaller number of a and b.
MMOB
statement
Simons
MMOB sprite, x1, y1, x2, y2, size, speed
Makes a sprite visible and moves it between the specified coordinates, with the speed: 1 = slowest, 255 = fastest. size 0 = normal, 1 = doubled in x direction, 2 = doubled in y direction, 3 = doubled in both directions.
MOB OFF
statement
Simons
MOB OFF sprite
Makes a sprite not visible.
MOB SET
statement
Simons
MOB SET sprite, block, color, priority, mode
Defines parameters of a sprite. block is the number of the memory block specified in the DESIGN statement; color is the color marked with B (for high resolution) or C (for multicolor) in the @ statements; priority is 0 = the sprite covers the screen contents, 1 = the sprite appears behind the screen contents; mode• is 0 = high resolution, 1 = multicolor.
MOD
function
Simons Enterprise
MOD(a, b)
Modulo function.
MONITOR
command
Plus/4
MONITOR
Enters the machine code monitor.
MOVE
statement
Spectrum
MOVE …NO INFO
Moves something on the microdrive. Details unknown.
Simons
MOVE row, column, width, height, row2, column2
Copies a selected area of the character screen to another place.
MOVSPR
statement
C128
MOVSPR sprite, {x, y|a # s}
Moves a sprite to another location. x and y may be absolute or relative coordinates, or instead, the sprite can be moved by angle a (0 to 360) and speed s (0 to 15).
MULTI
statement
Simons
MULTI a, b, c
Switches to multicolor graphic screen and sets colors.
MUSIC
statement
Simons
MUSIC length, music$
Plays music defined in music$: a CLR character and a digit specifies the voice; letters CDEFGAB the notes; SHIFT+CDEFGAB are notes with #; numbers 0–8 are octaves; Z is pause; function keys are for the note length. length is the overall length of the notes: 1 = longest, 255 = shortest.
NAME
auxiliary
Enterprise
An auxiliary keyword for OPEN.
NET
auxiliary
Enterprise
An auxiliary keyword for CLEAR.
NET CHANNEL
option
Enterprise
ASK NET CHANNEL n
Returns the channel number from which there is data in a network buffer waiting to be read. When the first byte is read from this channel, NET CHANNEL moves on to pointing at the next channel. 255 is returned if no more channels have data.
NET MACHINE
option
Enterprise
ASK NET MACHINE n
Returns the network number of the remote machine.
NET NUMBER
option
Enterprise
SET NET NUMBER n
Sets the computer’s network address number. n must be 1 to 32.
NEW
command
all
NEW
Deletes the program and variables stored in the memory.
NEW ALL
statement
Enterprise
NEW ALL
Deletes all programs and variables, and returns to program 0.
NEXT
statement auxiliary
all
NEXT [variable][, …]
Returns to the FOR statement specifying the loop with variable or if it’s omitted, to the recent one. If several variables are specified, it continues the first loop, then when it’s finished, the second loop, and so on.
Sinclair
NEXT variable
On Plus/4, also an auxiliary keyword for RESUME.
NO ERROR
statement
Simons
NO ERROR
Switches back to the normal error handling of BASIC.
NOT
operator
all
NOT x
Returns the bitwise NOT value of x.
NRM
statement
Simons
NRM
Switches back to the character screen from the graphic one.
NUMBER
auxiliary
Enterprise
An auxiliary keyword for ENVELOPE.
NUMERIC
statement
Enterprise
NUMERIC variable[, …]
Declares numeric variables or arrays. If within a DEF block, they’re local.
OFF
statement auxiliary
Simons
OFF
Switches the FLASH statement off.
Enterprise
an auxiliary keyword for SET and TRACE.
OLD
command
Simons
OLD
Restores the program after a NEW statement.
ON
statement auxiliary
Commodore|Enterprise
ON x {GOSUB|GOTO} line[, …]
Evaluates x. Depending on its value, it executes a GOSUB or GOTO statement to the given line: if x = 1, the first one, if x = 2, the second one, and so on. If x is less than 1 or more than the number of line numbers, the execution continues on the next statement. All line numbers must be numeric constants.
On Plus/4, also an auxiliary keyword for APPEND, BACKUP, COLLECT, COPY, DIRECTORY, DLOAD, DSAVE, HEADER, RENAME and SCRATCH. On C128, also an auxiliary keyword for BOOT, CATALOG, CONCAT, DCLEAR, DCLOSE, DOPEN and DVERIFY. On Enterprise, also an auxiliary keyword for SET and TRACE.
ON ERROR
statement
Simons
ON ERROR: GOTO line
Upon an error, jumps to line.
ON KEY
statement
Simons
ON KEY a$: GOTO line
If a key which is listed in a$ is pressed it jumps to line, placing the key in ST.
OPEN
statement
Commodore
OPEN lf, dev, sec, a$
Opens a logical file number lf on the device dev. sec is a secondary address that may be needed on some devices, and a$ is a file name or a command to be sent to the device. (See device in Concepts.)
Enterprise
OPEN £channel:[NAME] {device|filename} [ACCESS {INPUT|OUTPUT}]
Connects a device or a filename to a channel. ACCESS INPUT (default) attempts to use an existing file. ACCESS OUTPUT attempts to create a new file.
OPEN#
statement
Spectrum
OPEN# …NO INFO
Opens a file on the microdrive. Details unknown.
OPTION
command
Simons
OPTIONn
After n = 10, Simons’ BASIC keywords will be LISTed inverted.
OPTION ANGLE
statement
Enterprise
OPTION ANGLE {DEGREES|RADIANS}
Selects the base unit for subsequent angle operations. Default is RADIANS.
OR
operator
all
x OR y
Returns the bitwise OR value of the operands.
ORD
function
Enterprise
ORD(a$)
Returns the ASCII code of the first character of a$, according to the ASCII table of the computer. Same as ASC and CODE.
OUT
statement
Spectrum|Enterprise
OUT port, byte
Sends the byte to the port.
Simons
OUT
Turns ON ERROR off.
OVER
statement modifier
Spectrum
OVER o
Sets the overprinting mode for graphic statements. o 0 = off, 1 = on. Overprinting means the new contents will be XOR mixed with the old contents. Can be used as a statement or a modifier for graphic statements.
P
auxiliary
C128
Auxiliary keyword for BLOAD, BSAVE.
PAGE
command
Simons
PAGE n
Sets how many screen lines should LIST use. If n = 0, switches back to normal listing.
PAINT
statement
Plus/4
PAINT [colortype][, [x, y][, mode]
Paints an area, starting from the point x, y or the graphic cursor. If mode is 0, the painting finishes at non-background points; if 1, it finishes at background points.
Simons
PAINT x, y, dmode
Same as on Plus/4, just the order of parameters is different. dmode: see ANGL.
PALETTE
option
Enterprise
SET [£chan:] PALETTE a, b, c, d, e, f, g, h
Sets the values of the first 8 colors of the palette which are used by SET PAPER and SET INK. In color mode 0, a and b are used. In color mode 1, a to d are used. Colors are specified by color codes 0 to 255 or by the RGB function. The second half of the 16 color palette can be specified by SET BIAS.
PAPER
statement modifier option
Spectrum
PAPER p
Sets the paper color of graphic statements. p 0–7 = a color, 8 = transparent, 9 = contrast. Can be used as a statement or a modifier for graphic statements.
Enterprise
SET [£chan:] PAPER p
PAUSE
statement
ZX81
PAUSE time
Pauses the execution for time 1/50 seconds or until a key is pressed.
{L}Simons
PAUSE message$, s
Prints message$ and pauses the execution for s seconds.
PEEK
function
all
PEEK(address)
Returns the byte value stored at the address in the memory.
PEN
function
C128
PEN(n)
Returns information about the light pen: n 0 = the x coordinate, 1 = the y coordinate, 2 and 3 = same on the 80 column screen, 4 = the fire button.
PENX
function
Simons
PENX
Returns the x coordinate of the light pen.
PENY
function
Simons
PENY
Returns the y coordinate of the light pen.
PI
reserved_variable
Spectrum Enterprise
PI
Returns the value of π = 3.141596… Same as π.
PING
statement
Enterprise
PING
Produces a ping sound.
PITCH
auxiliary
Enterprise
An auxiliary keyword used for SOUND.
PLACE
function
Simons
PLACE(needle$, haystack$)
Searches for the first occurrence of needle$ in haystack$ and returns the character offset, or 0 if not found.
PLAY
statement
Simons
PLAY mode
mode: 0 = turns music off, 1 = plays it and after it execution will continue, 2 = starts playing while execution continues.
C128
PLAY a$
Plays a piece of music stored in a$. Its elements include (x means a digit): Vx = voice (1 to 3); Ox = octave (0 to 6); Tx = envelope (see below); Ux = volume (0 to 15); Xx = filter (0 = off, 1 = on); A, B, C, D, E, F, G = notes; # = sharp; $ = flat; W = whole note; H = half; Q = quarter; I = eighth; S = sixteenth; . = dotted; R = rest; M = wait for all voices currently playing to end the current measure. Modifiers precede the notes they apply to.
Envelope numbers: 0 = piano, 1 = accordion, 2 = calliope, 3 = drum, 4 = flute, 5 = guitar, 6 = harpsichord, 7 = organ, 8 = trumpet, 9 = xylophone.
PLOT
statement
ZX81
PLOT x, y
Paints the screen element at coordinates x, y black. Actually, this means replacing the character there with a graphic character having one black quarter more. x must be between 0 and 63, y must be between 0 and 43.
Spectrum
A real pixel is plotted, so x must be between 0 and 255 and y between 0 and 175.
Simons
PLOT x, y, dmode
Plots a pixel. dmode: see ANGL.
Enterprise
PLOT [£chan:]{x, y[{,|;} …]{,|;}|ANGLE r|FORWARD d|BACK d|LEFT r|RIGHT r|ELLIPSE x, y|PAINT}
x and y are point coordinates. A list of coordinate pairs paints points at the given coordinates. When the pairs are separated by a , comma, the drawing beam is turned off; when they’re separated by a ; semicolon, it is turned on. Same is true at the end of the coordinate list. Drawing the first point, if the beam was previously on, a line is drawn to the point.
Five elements work with a turtle. r is an angle in degrees, and d is a distance in pixels. FORWARD and BACK moves the turtle forward or back, respectively, in the direction it is pointing to. LEFT and RIGHT turns the turtle left or right, respectively, and ANGLE sets its angle directly: 0 means right, and it is measured anticlockwise.
ELLIPSE draws an ellipse with the given axes. PAINT paints the area around the beam, till the edges drawn by colors different from the current COLOUR
All the elements can be specified many times, in any order.
The current COLOUR, INK, LINE MODE and LINE STYLE will be used.
POINT
function
Spectrum
POINT x, y
Returns the color of the graphic point: 0 = PAPER color, 1 = INK color. x must be 0 to 255, y 0 to 175.
POINTER
function
C128
POINTER(variable)
Returns the address of the variable.
POKE
statement
all
POKE address, value
Stores the value at the address in the memory.
POS
function
Commodore
POS(dummy)
Returns the logical position of the cursor in the screen line.
Enterprise
POS(haystack$, needle$[, offset])
Returns the position of needle$ in haystack$ from the offsetth character, or 0 if not found.
POT
function
Simons
POT(n)
Returns the value of paddle n (0 or 1).
C128
Same as in Simons but n can be between 1 and 4.
PRINT
statement
all (exceptions below)
PRINT [element][separator][…]
On Commodore systems, the PRINT keyword can be abbreviated to a ? question mark.
An element can be a valid expression of any type or a special PRINT modifier: SPC or TAB (see there).
separators can be the following:
; (semicolon) puts the cursor immediately after the last printed character
, (comma) puts the cursor to the next comma-separated column
’ (apostrophe) only on Spectrum puts the cursor at the beginning of the next row
If the statement ends with no separator, the cursor is put at the first column of the next row.
Comma-separated columns: the screen is horizontally split into fixed columns. A comma in a PRINT statement puts the cursor to the next column, or if the rightmost column is reached, the first character of the next row.
Commodore – 4 columns, 10 characters wide
ZX81 – 2 columns, 11 characters wide
Regularly, positive numbers are printed with a leading space character; negative numbers have a – minus character instead. Fractional numbers are printed without a leading zero (.5 and –.5 instead of 0.5 and –0.5).
On Enterprise, a £chan channel specification may also be present. An element may be USING {ln|string}: where ln is the number of an IMAGE statement defining the printing format, or string may define it directly.
PRINT#
statement
Commodore
PRINT#lf, [element][separator][, …]
The same as PRINT but to the file opened with logical file number lf. In this statement, the keyword PRINT cannot be abbreviated by a ? question mark.
PRINT USING
statement
Plus/4
PRINT USING format; values
Creates a formatted printout. In format, the following characters are used:
# = place for a digit or character
+ = place for a positive sign
– = place for a positive or negative sign
. = place for a decimal point
, = place for a separator
$ = place for a dollar symbol
^^^^ = place for the exponent
= = centered
> = right adjusted
PROC
statement
Simons
PROC label
Marks a line with a label. It isn’t in " quotation marks. No other statements can follow it on the same line: all the rest of the line is the label. Such labels can be called without return by CALL or with return by EXEC.
PROGRAM
statement
Enterprise
PROGRAM name[(variable[, …])]
Defines the name of the current program to be used in CHAIN and SAVE. variables are passed by value by CHAIN.
PROMPT
auxiliary
Enterprise
An auxiliary keyword for INPUT.
PUDEF
statement
Plus/4
PUDEF a$
Redefines the output characters in PRINT USING with a$ which can contain up to 4 characters:
1st = the separator
2nd = the comma
3rd = the decimal point
4th = the $ symbol
RAD
function
Enterprise
RAD(x)
Returns x degrees in radians.
RADIANS
auxiliary
Enterprise
An auxiliary keyword for OPTION ANGLE.
RAND
statement
ZX81
RAND [x]
Sets the random number generator seed to x. If x is omitted or 0, the seed will be taken from the number of frames generated so far on the television. Same as RANDOMIZE.
RANDOMIZE
statement
Spectrum|Enterprise
RANDOMIZE [x]
Sets the random number generator seed to x. If x is omitted or 0, the seed will be taken from the number of frames generated so far on the television. Same as RAND.
On the Spectrum keyboard, it’s spelled RAND, but on the screen it is RANDOMIZE.
RCLR
function
Plus/4
RCLR(colortype)
Returns the color assigned to the colortype.
RCOMP
statement
Simons
RCOMP: statements[: ELSE: statements]
Evaluates the condition of the most recent IF again, and executes either the statements of the true branch or the false one.
RDOT
function
Plus/4
RDOT(n)
Returns information about the graphic cursor, depending on n:
0 = the x coordinate
1 = the y coordinate
2 = the colortype
READ
statement
all, except ZX81
READ variable[, …]
Reads one or more values from the DATA lines to the variables. The values and the variables must match in type.
Enterprise
READ [IF MISSING {ln|EXIT DO}:] variable[, …]
If there is no more DATA, and IF MISSING is included, a GOTO ln or an EXIT DO is executed.
REC
statement
Simons
REC x, y, width, height, dmode
Draws a rectangle. dmode: see ANGL.
RECORD
statement
C128
RECORD lf, rec[, byte]
Sets a file pointer of a relative file opened with logical file number lf to the record rec and byte byte.
RED
reserved_constant
Enterprise
RED
The color red = RGB(1, 0, 0).
REDIRECT
statement
Enterprise
REDIRECT FROM £ch1 TO £ch2
Redirects input from channel ch1 to ch2 until the end of the file is reached, the program is halted, or a later REDIRECT statement is issued with ch2 = 255.
RELEASE
auxiliary
Enterprise
An auxiliary keyword for ENVELOPE.
REM
statement function
all (exceptions below)
REM [text]
Does not do anything. Everything to the end of the line is ignored. This is the way to include comments in the program list.
Enterprise
Keyword REM may be abbreviated by an ! exclamation point.
REM(a, b)
Returns the remainder of a divided by b.
REM1
option
Enterprise
SET REM1 {ON|OFF}
Controls remote control switch 1. (Also controlled by tape operations.)
REM2
option
Enterprise
SET REM2 {ON|OFF}
Controls remote control switch 2. (Also controlled by tape operations.)
RENAME
statement
Plus/4
RENAME old$ to new$[, Ddev] [{ON|,} Uunit]
Renames a file old$ to a new name new$ in device dev on unit unit.
RENUMBER
command
Plus/4
RENUMBER from[, step][, beginning]
Renumbers the lines of the program. The first line will get the number from, and further lines will be increased by step. The default is 10 for both. If beginning is given, that is the first line of the program to be renumbered. Line numbers in GOTO and GOSUB statements are also renumbered.
Simons
RENUMBER from, beginning
Same as on Plus/4 but lacks step and doesn’t renumber line numbers in GOTO and GOSUB statements. However, they aren’t needed in Simons’ BASIC since there are PROC, CALL and EXEC.
Enterprise
RENUMBER [{line1 TO line2|blockname}] [AT at] [STEP step]
Can renumber the whole program or just a part of it. line1 and line2 can be line numbers, FIRST or LAST. blockname is the name of a DEF or HANDLER block. If no lines are specified, it means the whole program. at is the first new number, or the number of the first line to be renumbered. step defaults to 10.
References to renumbered lines are changed. RENUMBER cannot change the order of line, so if the renumbered lines would overlay or surround lines not renumbered, or would be put into a new place in the sequence, the command is not executed.
REPEAT
statement
Simons
REPEAT
Marks the beginning of a REPEAT–UNTIL loop
RESET
statement
Simons
RESET line
Restores the DATA pointer to the beginning of line line.
RESTORE
statement
all, except ZX81
RESTORE
Restores the DATA pointer to the beginning of the program, so subsequent READ statements will read the data from the first DATA line.
Plus/4 Spectrum Enterprise
RESTORE [line]
If line is given, restores the DATA pointer to the beginning of that line.
RESUME
statement
Plus/4
RESUME [line|NEXT]
Resumes the execution from the error handling routine. If line is specified, it will return to that line. With NEXT, execution continues with the next statement. If neither is given, it tries to execute the statement which caused the error again.
Simons
RESUME
Switches an ON KEY statement, after switching it off, on again.
RETRACE
statement
Simons
RETRACE
Puts the TRACE windows back on the screen after a clear screen.
RETRY
statement
Enterprise
RETRY
Used as an exit from an exception handler, returns control to the statement which caused the exception.
RETURN
statement
all
RETURN
Finishing the current subroutine, returning to the recently executed GOSUB statement.
RGB
function
Enterprise
RGB(red, green, blue)
Returns the color number by mixing red, green and blue. Each color ingredient may be specified from 0 to 1.
RGR
function
Plus/4
RGR(dummy)
Returns the current mode as set in the GRAPHIC statement.
RIGHT
auxiliary
Enterprise
An auxiliary keyword used for SOUND.
RIGHT$
function
all, except Sinclair
RIGHT$(a$, x)
Returns x characters from the right side, i.e. from the end of a$.
RIGHTB
statement
Simons
RIGHTB r1, c1, r2, c2
Scrolls a rectangle of the character screen right. From the left, empty space comes in.
RIGHTW
statement
Simons
RIGHTW r1, c1, r2, c2
Scrolls a rectangle of the character screen right. From the left, the contents scrolled out come in.
RLOCMOB
statement
Simons
RLOCMOB sprite, x, y, size, speed
Moves a sprite earlier made visible with MMOB
RLUM
function
Plus/4
RLUM(colortype)
Returns the luminosity of the color assigned to colortype.
RND
function
all (exceptions below)
RND(x)
Returns a random (actually, pseudorandom) number. x is a dummy.
Commodore
if x > 0, it returns the next number in a random series
if x < 0, it returns the same number for the same x
if x = 0, it returns a number based on the internal clock
Sinclair
RND
Enterprise
RND[(x)]
Returns a random number between 0 and (less than) 1, or if x is given, an integer between 0 and (less than) x.
ROT
statement
Simons
ROT angle, size
Sets the rotation angle (in 45° steps) and zoom size of shapes to be drawn with DRAW.
ROUND
function
Enterprise
ROUND(x, n)
Rounds x to n decimal places.
RSPCOLOR
function
C128
RSPCOLOR(n)
Returns the multicolor sprite colors n 1 or 2.
RSPPOS
function
C128
RSPPOS(sprite, n)
Returns information about a sprite. n 0 = x position, 1 = y position, 2 = the speed.
RSPRITE
function
C128
RSPRITE(sprite, n)
Returns information about a sprite. n: 0 = on, 1 = color, 2 = covered by contents, 3 = x zoom, 4 = y zoom, 5 = multicolor. Except the color, any parameter returns 0 = off or 1 = on.
RTRIM$
function
Enterprise
RTRIM$(s$)
Removes spaces from the end of s$.
RUN
command
all (exceptions below)
RUN [line]
Runs the program from the first line, or from the specified line. Before that, deletes all variables.
Enterprise
RUN [{[{[£chan:]filename|devicename}](variable[, …])|line}]
If a filename is given, the program is loaded and run. Parameter variables can be passed to the program, they must correspond with parameters declared in PROGRAM.
RWINDOW
function
C128
RWINDOW(n)
Returns information about the screen window. n 0 = number of rows, 1 = number of columns, 2 = returns 40 or 80, based on the active screen mode.
SAVE
command
Commodore
SAVE filename$[, device]
Saves a program to the specified device.
Sinclair
SAVE filename$
Spectrum
Saves the variables along with the program.
SAVE filename LINE line
After LOADing the program back, it will automatically start at line.
SAVE filename DATA [$]()
Saves an array. If the $ symbol is present, it’s a string array; without it, a numeric array.
SAVE filename CODE addr, len
Saves len bytes from address addr.
SAVE filename SCREEN$
Saves the screen.
Enterprise
SAVE [{[ALL] [£chan:]filename|devicename}]
If no filename is given, the PROGRAM name is used. SAVE ALL saves all programs in memory.
SCALE
statement
Plus/4
SCALE mode
Selects the scaling mode on the graphic screen. Default is 0 when the coordinates are the same as the physical coordinates; if it is 1, both x and y coordinates run from 0 to 1023. The physical resolution doesn’t change.
SCNCLR
statement
Plus/4
SCNCLR
Clears the active screen.
C128
SCNCLR [mode]
If mode is present, it clears the screen specified (see GRAPHIC).
SCRATCH
statement
Plus/4
SCRATCH file$[, Ddev] [{ON|,} Uunit]
Deletes one or more file$s from the disk in device dev on unit unit.
SCREEN$
function auxiliary
Spectrum
SCREEN$(row, column)
Returns the character at the given character position. row must be 0 to 23, column 0 to 31. Cannot recognize UDG characters.
Also an auxiliary keyword for LOAD and SAVE.
SCRLD
statement
Simons
SCRLD lf, dev, sec, name$
Loads the character screen from file. Parameters are like in the OPEN statement.
SCRSV
statement
Simons
SCRSV lf, dev, sec, name$
Saves the character screen. Parameters are like in the OPEN statement.
SCROLL
statement option
ZX81
SCROLL
Scrolls the contents of the screen one row up, deleting the top line. Subsequent PRINT statements will write in the bottom row.
Enterprise
SET [£chan:] SCROLL {ON|OFF}
Turns automatic scroll on or off.
SET [£chan:] SCROLL {DOWN|UP} n, m
Scrolls the screen down or up from line n–32 to m–32.
SEC
function
Enterprise
SEC(x)
Returns the secant of x.
SECURE
command
Simons
SECURE 0
After executing it, lines marked with DISAPA won’t be listed, only their line numbers, but they will be executed anyhow.
SELECT
statement
Enterprise
SELECT [CASE] expression
CASE {values|IS relation|ELSE}
…statements…
END SELECT
Evaluates expression, and depending on the result, executes the statements following either CASE line. Several CASE clauses can be specified, followed by one or more statements. values can be one or more values and/or ranges (in the format lowest TO highest), separated by commas. relation is an expression beginning with a relational operator. If the result of expression is equal to either value or falls within either range, or expression IS relation is true, the following statements are executed. If no CASE line is matched, CASE ELSE is executed if specified. Only one CASE ELSE is allowed and it must be the last one.
SERIAL BAUD
option
Enterprise
SET SERIAL BAUD m
Sets the baud rate for the RS232 port and the network. m is a mode parameter: 0 – 50, 1 – 75, 2 – 110, 3 – 134.5, 4 – 150, 5 – 200, 6 – 300, 7 – 600, 8 – 1200, 9 – 1800, 10 – 2400, 11 – 3600, 12 – 4800, 13 – 7200, 14 – 9600, 15 – 9600.
SERIAL FORMAT
option
Enterprise
SET SERIAL FORMAT b
Defines the word format for the serial device drive. b is a byte controlling the format:
bit 0: 0 – 8 bits, 1 – 7 bits
bit 1: 0 – no parity
bit 2: 0 – even parity, 1 – odd parity
bit 3: 0 – two stop bits, 1 – one stop bit
Further bits must be 0. Default is 0.
SET
statement
Enterprise
SET {option|n} value
Sets an option to a value. Specifying a number n instead will reach an operating system variable.
SGN
function
all
SGN(x)
Returns the signum of x, i.e. 1 for positive numbers, –1 for negative ones, and 0 for 0.
SIN
function
all
SIN(x)
Returns the sine of x radians.
SINH
function
Enterprise
SINH(x)
Return the hyperbolic sine of x.
SIZE
function
Enterprise
SIZE(array[, dim])
Returns the number of elements in the array or in its dimth dimension if specified.
SLEEP
statement
C128
SLEEP sec
Delays the program for sec seconds.
SLOW
statement
ZX81|C128
SLOW
Turns the screen off, after a FAST statement. An error, the end of the program or a NEW invokes SLOW, too.
SOUND
statement
Plus/4
SOUND voice, freq, length
Emits a sound from the voice which can be 0 or 1 for music, or 2 for white noise. freq is the frequency between 0 to 1023 and length is between 0 and 65535.
C128
SOUND voice, freq, length[, dir, m, s, w, p]
In addition to the Plus/4 version, the statement can sweep through a range of frequencies. Direction is set by dir: 0 = up, 1 = down, 2 = oscillate. m is the minimum frequency, s is the step value, w the waveform: 0 = triangle, 1 = sawtooth, 2 = variable, 3 = noise, and p is the pulse width.
Enterprise
SOUND £chan: PITCH p, DURATION d, LEFT l, RIGHT r, SOURCE so, STYLE st, ENVELOPE e, SYNC sy, INTERRUPT
Provides overall control of a sound. Parameters may be listed in any order. p (0 to 127) raises the pitch by p semitones. Default is 37 = middle c. The duration of the sound is d/50 seconds, default 50. l and r are the overall volume of the two stereo output channels, from 0 (no sound) to 255 (loudest, the default). so is the tone generator, 0 to 3 (default 0) where 3 is the noise generator. st is the style parameter (0 to 255). e is the number of envelope specified in the ENVELOPE statement; default is 255, the built-in envelope. Several sounds can be synchronized by specifying the same sy values. INTERRUPT causes the new sound to replace any sound from the same source.
SOUND BUFFER
option
Enterprise
SET SOUND BUFFER b
Sets the size of the sound envelope storage area, in phases, 1 to 255, the default is 20.
SOUND STYLE
option
Enterprise
SET SOUND STYLE s
Sets the value for the STYLE parameter in a SOUND statement. On tone channel 0: s = 16 low distortion, 32 medium distortion, 48 high distortion, 64 use high pass filter (tone channel 1 is clock), 128 ring modulation with channel 2. On tone channel 1: as channel 0, but high pass filter uses tone channel 2, ring modulator uses channel 3. On tone channel 2: as channel 0, but high pass filter uses channel 3, ring modulator uses channel 0. On channel 3 (noise channel): 1, 2, 3 use tone channel 0, 1 or 2 as clock frequency, instead of the standard 31.25 KHz frequency, 4, 8, 12 select noise frequency from 15, 11 or 9-bit polynomial counters, instead of standard 17-bit counter, 16 substitute a 7-bit polynomial counter for the 17-bit counter, 32 use low pass filter on noise channel, using tone channel 2 as clock, 64 use high pass filter on noise channel, using tone channel 0 as clock, 128 use ring modulator with tone channel 1.
SOURCE
auxiliary
Enterprise
An auxiliary keyword used for SOUND.
SPC
special_function
Commodore
SPC(x)
Returns x space characters. This function works only in the PRINT statement.
SPEAKER
option
Enterprise
SET SPEAKER {ON|OFF}
Sets the sound output on or off.
SPEEK
function
Enterprise
SPEEK(segment, address)
The same as PEEK but refers to a segment, additionally.
SPOKE
statement
Enterprise
SPOKE segment, address, value
The same as POKE but refers to a segment, additionally.
SPRCOLOR
statement
C128
SPRCOLOR m1, m2
Specifies the two colors for multicolor sprites.
SPRDEF
command
C128
SPRDEF
Starts the built-in sprite designer.
SPRITE
statement
C128
SPRITE sprite[, on][, color][, priority][, xz][, yz][, mode]
Sets parameters for a sprite. on is 0 = turns it off, 1 = turns it on. color is the foreground color. priority is 0 = sprite covers the screen contents, 1 = screen contents cover the sprite. xz and yz are the zoom in x and y directions.
SPRSAV
statement
C128
SPRSAV source, target
Copies the image of a sprite to a string or back. Both source and target can be a number, this means copying to another sprite. If target is a string variable, the image is stored in it. If source is a string variable, the sprite takes the image stored in it (only the first 63 bytes, additional content is ignored).
SQR
function
all
SQR(x)
Returns the square root of x.
SSHAPE
statement
Plus/4
SSHAPE a$, x1, y1[, x2, y2]
Stores a part of the graphic screen in the variable a$. x1, y1 are the top left corner, and x2, y2 or the graphic cursor are the bottom right corner. The shape can be later pasted back on the with GSHAPE.
ST
reserved_variable
Commodore
ST
Returns the status code of the device used last.
START
statement
Enterprise
START
If no program is loaded, loads the first program from channel 106 and runs it. If any program is loaded, runs that one.
STASH
statement
C128
STASH bytes, inaddr, bank, exaddr
Copies data from the operative memory to the extended memory. See parameters at FETCH.
STATUS
option
Enterprise
SET STATUS {ON|OFF}
Turns the status line at the top of the display on or off.
STEP
auxiliary
all
Auxiliary keyword for FOR.
Enterprise
Also an auxiliary keyword for AUTO and RENUMBER.
STOP
statement
all
STOP
Stops the execution, issuing an error message.
STR$
function
all (exceptions below)
STR$(x)
Returns x as a string, in the same format as PRINT displays it.
Enterprise
Returned string does not include any space character.
STRING
statement
Enterprise
STRING[*n] variable[*n][, …]
Declares one or more string variables with a given length of n characters (default 132). Adding *n after the keyword STRING specifies the length for all variables mentioned in the statement; specifying *n for any of them overwrites this.
STYLE
auxiliary
Enterprise
An auxiliary keyword used for SOUND.
SWAP
statement
C128
SWAP bytes, inaddr, bank, exaddr
Swaps the contents of the operative memory and the extended memory. See parameters at FETCH.
SYNC
auxiliary
Enterprise
An auxiliary keyword used for SOUND.
SYS
function
Commodore
SYS addr
Execute the machine code program from the memory address addr.
C128
SYS addr[, a][, x][, y][, s]
Same as in general Commodore, but the parameters are loaded to the accumulator, the X and Y registers, and the status register, respectively.
TAB
special_function
all
TAB(x)
Puts the cursor on the column x. This function works only in the PRINT statement.
On ZX81, x is interpreted modulo 32. Then, if column x is right from the cursor, it will move there; otherwise, it will move to the xth column of the next line.
TAN
function
all
TAN(x)
Returns the tangent of x radians.
TANH
function
Enterprise
TANH(x)
Returns the hyperbolic tangent of x.
TAPE LEVEL
option
Enterprise
SET TAPE LEVEL v
Controls the volume level for saving to tape. v is in the range 1–6•, where 1 is about 40 mV and each level is a double volume. Default •2•.
TAPE SOUND
option
Enterprise
SET TAPE SOUND {ON|OFF}
Controls transmission of sound from tape input to sound output.
TEMPO
statement
C128
TEMPO n
Sets the tempo of the PLAY statement. n can be 0 to 255, and it means a whole note length = 19.22/n seconds.
TEST
function
Simons
TEST(x, y)
Returns the state of a pixel on the graphic screen.
TEXT
statement
Simons
TEXT x, y, a$, dmode, size, i
Prints a$ on the graphic screen in zoom factor size, separating letters by i pixels; in a$, CTRL+A = uppercase mode, CTRL+B = lowercase mode.
Enterprise
TEXT [c]
Closes the standard graphics page if it was open, and opens a text page covering the entire display except the status line. c is the number of columns, 40 or 80.
THEN
auxiliary
all
Auxiliary keyword for IF.
TI
reserved_variable
Commodore
TI
Returns the number of 60th seconds elapsed since the computer was switched on.
TI$
reserved_variable
Commodore
TI$
Returns the setting of the internal clock, in the format HHMMSS. When the computer is switched on, it is 000000. It can be set with a statement TI$="040831"
TIME
statement
Enterprise
TIME time
Sets the internal clock. time is a string in the format "hh:mm:ss".
TIME$
function
Enterprise
TIME$
Returns the current time in the format "hh:mm:ss".
TIMER
option
Enterprise
SET TIMER t
Start a timer at t seconds (maximum 255) which will cause a software interrupt when it counts down to zero, then it stops. t = 0 stops the timer without causing an interrupt.
TO
auxiliary
all
Auxiliary keyword for FOR. On Plus/4, also an auxiliary keyword for BACKUP, COPY and DRAW. On C128, also an auxiliary keyword for BSAVE and CONCAT. On Enterprise, also an auxiliary keyword for CAPTURE, COPY, DELETE, DIM, DISPLAY, LIST, LLIST, REDIRECT, RENUMBER and TRACE.
TOGGLE
statement
Enterprise
TOGGLE {option|n}
Toggles a system option to the opposite state. Specifying a number n instead will reach an operating system variable. Works on options which have only an ON and OFF state.
TRACE
statement
Simons
TRACE n
If n = 10 turns tracing on: in the upper right corner it displays the numbers of the last six program lines executed.
Enterprise
TRACE {ON [TO £chan]|OFF}
When ON, sends the numbers of lines being executed to the channel chan or channel 0 if omitted.
TRAP
statement
Plus/4
TRAP [line]
Turns error catching on: any subsequent error will send execution to line line. If no line is specified, error catching is turned off.
TROFF
statement
Plus/4
TROFF
Turns TRON off.
TRON
statement
Plus/4
TRON
Turns tracking mode on. In tracking mode, the line number of each program line executed will be displayed between [] brackets.
TRUNCATE
function
Enterprise
TRUNCATE(x, n)
Cuts n decimal places from x.
TYPE
statement
Enterprise
TYPE
After asking for confirmation, exits BASIC with destroying programs and variables in memory, and starts the built-in word processor.
U
auxiliary
Plus/4
Auxiliary keyword for APPEND, BACKUP, BLOAD, BOOT, BSAVE, CATALOG, COLLECT, CONCAT, COPY, DCLEAR, DCLOSE, DIRECTORY, DLOAD, DOPEN, DSAVE, DVERIFY, HEADER, RENAME and SCRATCH.
UBOUND
function
Enterprise
UBOUND(array[, dim])
Returns the upper bound of the array in the dimth dimension or in the only one if dim is omitted.
UCASE$
function
Enterprise
UCASE$(s$)
Returns s$ converted to uppercase characters.
UNPLOT
statement
ZX81
UNPLOT x, y
Paints the screen element at coordinates x, y white. Actually, this means replacing the character there with a graphic character having one white quarter more. x must be between 0 and 63, y must be between 0 and 43.
UNTIL
statement auxiliary
Plus/4
Auxiliary keyword for DO and LOOP.
Simons
UNTIL condition
Repeats the REPEAT–UNTIL loop until condition turns true.
UPB
statement
Simons
UPB r1, c1, r2, c2
Scrolls a rectangle of the character screen up. From the bottom, empty space comes in.
UPW
statement
Simons
UPW r1, c1, r2, c2
Scrolls a rectangle of the character screen up. From the bottom, the contents scrolled out come in.
USE
statement
Simons
USE format$, n
Prints n in the specified format$ where the place of digits are marked #.
USR
function
Commodore|Sinclair
USR(x)
Calls a machine code program at address 784 (decimal), giving it x as a parameter. Returns a value from the machine code program.
Spectrum
USR char$
Taking a character from a to u or an UDG, returns the address of the bit pattern for that UDG character. POKEing 8 values to this address and the following 7 will redesign the UDG.
Enterprise
USR(address, x)
Calls the address, giving x to the HL register pair. Returns the value received back in HL.
VAL
function
all
VAL(a$)
Returns a numeric value stored in a$ as a string. On Sinclair, a$ may contain an expression and it will be evaluated.
VAL$
function
Spectrum
VAL$ a$
Evaluates a$ as a string expression.
VERIFY
command
Commodore
VERIFY [filename$[, device]]
Verifies a program from the specified device, comparing it to the program stored in memory. If filename$ is specified (not an empty string), the program with the appropriate name will be searched. Otherwise, the first one is compared.
Enterprise
VERIFY [£chan:]filename°
VIDEO COLOUR
option
Enterprise
SET VIDEO COLOUR v
Sets the color mode for subsequently opened video pages. On text pages, v must be 0. On high resolution graphics pages, the color modes are the following: v = 0 2 colors, horizontal resolution 640; 1 4 colors, res. 320; 2 16 colors, res. 160; 3 256 colors, res. 80. On low resolution pages, the horizontal resolution is halved. Keyword COLOR can be used instead of COLOUR.
VIDEO MODE
option
Enterprise
SET VIDEO MODE m
Sets the video mode for subsequently opened pages. m = 0 40 column text, 1 high resolution graphics, 2 80 column text, 5 low resolution graphics, 15 attribute graphics.
VIDEO X
option
Enterprise
SET VIDEO X x
Defines the horizontal size of video pages subsequently to be opened, in x character positions from 2 to 42.
VIDEO Y
option
Enterprise
SET VIDEO Y y
Defines the vertical size of video pages subsequently to be opened, in y character positions from 1 to 255.
VOL
statement
Plus/4
VOL volume
Sets the sound volume between 0 (off) to 7 (loudest).
Simons
The same, but 15 is the loudest.
WAIT
statement
Commodore
WAIT address, a[, b]
a and b are one byte long values. The computer will wait until the bits at address, compared to a and b, give appropriate values. If only a is present, the execution continues when PEEK(address) AND a <> 0 – if b is present, the execution continues when (PEEK(address) EOR b) AND a <> 0.
Enterprise
WAIT [DELAY] n
Waits for n seconds. The keyword DELAY is optional.
WAVE
statement
Simons
WAVE voice, waveform
Sets the waveform for the voice (1–3). waveform is an 8 digits long binary literal where the meaning of the bits are the following: 7 = white noise, 6 = square, 5 = sawtooth, 4 = triangle, 3 = testbit, 2 = modulation, 1 = synchronization, 0 = gate bit.
WHEN EXCEPTION USE
statement
Enterprise
WHEN EXCEPTION USE handler
…
END WHEN
Specified the exception handler to be used when an exception occurs inside the WHEN block.
WHILE
auxiliary
Plus/4
Auxiliary keyword in DO and LOOP.
WHITE
reserved_constant
Enterprise
WHITE
The color white = RGB(1, 1, 1).
WIDTH
statement
C128
WIDTH n
Sets the width of lines drawn. n can be 1 or 2.
WINDOW
statement
C128
WINDOW x1, y1, y2, y2[, clear]
Sets a logical window on the 40 or 80 column character screen. If clear is 1, the inside of the window will be cleared.
WORD$
function
Enterprise
WORD$(n)
Returns n converted to a two-byte string (first byte is least significant).
XOR
function
C128
XOR(a, b)
Returns the bitwise XOR value of a and b.
YELLOW
reserved_constant
Enterprise
YELLOW
The color yellow = RGB(1, 1, 0).
@
statement
Simons
@bits
After a DESIGN statement, describes a line of a shape. For high-resolution sprites, bits (a string literal with no " quotation marks) are 24 characters; for multicolor sprites, 12; for characters, 8. Applicable characters are: . = background color, B = foreground color, and in multicolor C and D = two additional colors (see CMOB and MOB SET).
:
separator
all, except ZX81
statement : statement …
Statement separator to use several statements in the same line. On ZX81, only one statement by line is allowed.
;
separator
all
… value; value …
Separator to delimit parameters in some situations.
,
separator
all
… value, value …
Separator to delimit parameters of statements and arguments of functions.
’
separator
Spectrum
… value ’ value …
One of the separators in the PRINT statement to put the cursor to the beginning of the next line.
+
operator
all
value + value
For numbers, addition operator. For strings, concatenation operator.
–
operator
all
value – value
Subtraction operator. For a single value, negation operator.
For LIST (and on Enterprise, DELETE), stands between two line numbers to specify “from–to”.
*
operator
all
value * value
Multiplication operator.
/
operator
all
value / value
Division operator.
↑
operator
Commodore|Spectrum
value ↑ value
Power operator.
**
operator
ZX81
value ** value
Power operator.
=
operator
all
value = value
1. Relational operator: true if the values are equal. 2. Assignment operator: assigns a value to a variable (variable=value), replacing the LET statement. 3. Used in some statements like FOR.
<
operator
all
value1 < value2
Relational operator: true if value1 is less than value2.
>
operator
all
value1 > value2
Relational operator: true if value1 is greater than value2.
<=
operator
all
value1 <= value2
Relational operator: true if value1 is less than or equal to value2. On most systems, can be written also =<.
>=
operator
all
value1 >= value2
Relational operator: true if value1 is greater than or equal to value2. On most systems, can be written also =>.
<>
operator
all
value1 <> value2
Relational operator: true if value1 is not equal to value2. On most systems, can be written also ><.
( )
separator
all
… (values) …
Enclosing separator for arguments of functions, and used in expressions.
On Sinclair, beyond the above, it is the substring marker, along with the keyword TO.
s$(a) means the ath character of s$
s$(a TO ) means the ath and following characters of s$
s$( TO b) means the first and following characters of s$, ending with the bth one
s$(a TO b) means the characters of s$ from the ath one to the bth one, inclusively
Also on the Sinclair, the ( ) parentheses aren’t required around the argument of a function if it is a single literal value or variable. If the function keyword is followed by an expression and there are no parentheses, it will be interpreted with only the first element as an argument.
"
separator
all
"string"
Enclosing separator to include literal strings. On Spectrum, two ("") are written if one " quotation mark needs to be printed inside " quotation marks.
""
symbol
ZX81
"string""string"
Serves as a replacement character for the " quotation mark inside literal strings. When printing the string, it appears as ". On ZX81, "" is a separate character, “double double quotation marks”. On Spectrum, two " quotation marks are used for this purpose.
#
symbol
Commodore
statement#lf…
On the Commodore systems, in some file related statements, serves as a prefix for the logical file number lf. Actually, it is a part of the keyword itself.
On ZX81, the character itself is not available.
£
symbol
Enterprise
…£chan…
In input–output statements, precedes channel numbers.
$
symbol
all
name$
1. Serves as a suffix at variable names to denote string variables. 2. Serves as a suffix for function names that result in a string. Actually, it is a part of the keyword itself.
Simons
$digits
A hexadecimal constant.
%
symbol
all, except Sinclair
name%
Serves as a suffix at variable names to denote integer variables. On ZX81, the character itself is not available.
Simons
%bits
A binary constant.
&
operator
Enterprise
…string&string…
Concatenation operator.
!
symbol
Enterprise
An abbreviation for keyword REM.
?
symbol
all, except Sinclair
On most systems (except Sinclair) it is the abbreviation of the PRINT statement.
.
symbol
Simons
A bit marking symbol in the @ statement.
π
reserved_variable
Commodore|ZX81
π
Returns the value of π = 3.141596… Same as PI.
On Commodore and ZX81, this Greek letter is available in the character set and can be reached from the keyboard.
Sources
Kőhegyi János (editor): Ismerd meg a BASIC nyelvjárásait! [Get Acquainted with Dialects of BASIC!] Műszaki Könyvkiadó. Series:
– 1. HT–1080Z, ABC80, ZX81. 1984.
– 2. ZX Spectrum, TI–99/4A, Proper–16/A. 1985.
– 3. Commodore 64, Commodore VIC 20, Sharp PC–1500. 1986.
– 4. Commodore 16, Commodore Plus/4, Commodore 128, Videoton TV Computer. 1989.
Láng Attila D.: TV–BASIC. A tévésorozat, amely történelmet írt. [TV–BASIC. The Television Series That Wrote History.] Private digital publication, 2021.
Plenge–Szczepanowsky: Simon’s [sic!] BASIC gyakorlatok. [Simons’ BASIC Exercises.] Data Becker–Novotrade, 1984.
Rochlitz András (ed.): Commodore 128 felhasználói kézikönyv. [User Manual] Novotrade Rt., 1987.
Sági Gyula: Ismerkedés a ZX81-gyel. [Getting Acquainted with the ZX81] Műszaki Könyvkiadó, 1985.
Tory Kálmán: Commodore 16 felhasználói kézikönyv. [User Manual]
Úry László dr.: Commodore 16, Commodore 116 BASIC és felhasználói kézikönyv. [BASIC and User Manual] LSI ATSZ, 1986.
Úry László dr.: Commodore 64 BASIC felhasználói kézikönyv. [User Manual] LSI ATSZ, 1984.
Vickers, Steven: Sinclair Spectrum BASIC Programming. Sinclair Research Limited, second edition 1983.
Vickers, Steven: Sinclair ZX81 BASIC Programming. Sinclair Research Limited, second edition 1981.
Vogel, James–Scrimshaw, Nevin B.: The Commodore 64 Music Book. Birkhauser Boston, Inc.
Wiese, William M., Jr.: Commodore 128 Programming Secrets. Osborne McGraw-Hill.
–: Enterprise Programming Guide. Enterprise Computers Ltd., 1984.
Wikipedia
KEYWORDS
485: ABS ACCESS ACOS ACS ALL ALLOCATE AND ANGL ANGLE APPEND ARC ASC ASK ASN ASIN AT ATN ATTR ATTRIBUTE ATTRIBUTES AUTO B BACKUP BANK BCKGNDS BEAM BEEP BEGIN BEND BFLASH BIAS BIN BLACK BLOAD BLOCK BLUE BOOT BORDER BOX BRIGHT BSAVE BUMP C CALL CAPTURE CAT CATALOG CAUSE CEIL CENTRE CGOTO CHAIN CHAR CHARACTER CHECK CHR$ CIRCLE CLEAR CLOSE CLOSE# CLR CLS CMD CMOB CODE COLD COLLECT COLLISION COLOR COLOUR CONCAT CONT CONTINUE COPY COS COSH COT CSC CSET CURSOR CHARACTER CURSOR COLOUR CYAN D DATA DATE DATE$ DCLEAR DCLOSE DEC DEF DEFAULT CHANNEL DEG DEGREES DELAY DELETE DESIGN DETECT DIM DIR DIRECTORY DISABLE DISAPA DISK DISPLAY DISPLAY GRAPHICS DISPLAY TEXT DIV DLOAD DO DOPEN DOWNB DOWNW DRAW DS DS$ DSAVE DUMP DUP DURATION DVERIFY EDIT EDITOR BUFFER EDITOR KEY EDITOR VIDEO EL ELSE END END DEF END HANDLER END IF END LOOP END PROC END SELECT END WHEN ENVELOPE EPS ER ERASE ERR$ ERRLN ERRN EXCEPTION EXEC EXIT EXIT DEF EXIT DO EXIT FOR EXIT HANDLER EXIT IF EXLINE EXOR EXP EXSTRING$ EXT EXTYPE FAST FAST SAVE FCHR FCOL FETCH FILL FILTER FIND FIRST FKEY FLASH FLUSH FN FOR FORMAT FP FRAC FRE FREE FROM GET GETKEY GLOBAL GO GOSUB GOTO GRAPHIC GRAPHICS GREEN GSHAPE HANDLER HEADER HELP HEX$ HI COL HIRES HRDCPY I IF IF MISSING IMAGE IN INF INFO INK INKEY INKEY$ INPUT INPUT# INSERT INST INSTR INT INTERRUPT INTERRUPT CODE INTERRUPT KEY INTERRUPT NET INTERRUPT STOP INV INVERSE IP JOY KEY KEY CLICK KEY DELAY KEY RATE L LAST LBOUND LCASE$ LEFT$ LEFTB LEFTW LEN LET LINE LINE INPUT LINE MODE LINE STYLE LIST LLIST LN LOAD LOCAL LOCATE LOG LOG10 LOG2 LOOK LOOP LORES LOW COL LPRINT LTRIM$ MAGENTA MAX MAXLEN MEM MERGE MID$ MIN MMOB MOB OFF MOB SET MOD MONITOR MOVE MOVSPR MULTI MUSIC NAME NET NET CHANNEL NET MACHINE NET NUMBER NEW NEW ALL NEXT NO ERROR NOT NRM NUMBER NUMERIC OFF OLD ON ON ERROR ON KEY OPEN OPEN# OPTION OPTION ANGLE OR ORD OUT OVER P PAGE PAINT PALETTE PAPER PAUSE PEEK PEN PENX PENY PI PING PITCH PLACE PLAY PLOT POINT POINTER POKE POS POT PRINT PRINT# PRINT USING PROC PROGRAM PROMPT PUDEF RAD RADIANS RAND RANDOMIZE RCLR RCOMP RDOT READ REC RECORD RED REDIRECT RELEASE REM REM1 REM2 RENAME RENUMBER REPEAT RESET RESTORE RESUME RETRACE RETRY RETURN RGB RGR RIGHT RIGHT$ RIGHTB RIGHTW RLOCMOB RLUM RND ROT ROUND RSPCOLOR RSPPOS RSPRITE RTRIM$ RUN RWINDOW SAVE SCALE SCNCLR SCRATCH SCREEN$ SCRLD SCRSV SCROLL SEC SECURE SELECT SERIAL BAUD SERIAL FORMAT SET SGN SIN SINH SIZE SLEEP SLOW SOUND SOUND BUFFER SOUND STYLE SOURCE SPC SPEAKER SPEEK SPOKE SPRCOLOR SPRDEF SPRITE SPRSAV SQR SSHAPE ST START STASH STATUS STEP STOP STR$ STRING STYLE SWAP SYNC SYS TAB TAN TANH TAPE LEVEL TAPE SOUND TEMPO TEST TEXT THEN TI TI$ TIME TIME$ TIMER TO TOGGLE TRACE TRAP TROFF TRON TRUNCATE TYPE U UBOUND UCASE$ UNPLOT UNTIL UPB UPW USE USR VAL VAL$ VERIFY VIDEO COLOUR VIDEO MODE VIDEO X VIDEO Y VOL WAIT WAVE WHEN EXCEPTION USE WHILE WHITE WIDTH WINDOW WORD$ XOR YELLOW @ : ; , ’ + – * / ↑ ** = < > <= >= <> ( ) " "" # £ $ % & ! ? . π
TYPES
auxiliary 48: ACCESS ALL AT ATTRIBUTE B CLR CODE D DATA DEGREES DELAY DURATION ELSE ENVELOPE EXCEPTION EXIT DO FIRST FROM HIRES I IF MISSING INTERRUPT L LAST LINE LORES NAME NET NEXT NUMBER OFF ON P PITCH PROMPT RADIANS RELEASE RIGHT SCREEN$ SOURCE STEP STYLE SYNC THEN TO U UNTIL WHILE
command 19: AUTO COLD CONT DELETE EDIT HELP LIST LOAD MONITOR NEW OLD OPTION PAGE RENUMBER RUN SAVE SECURE SPRDEF VERIFY
function 107: ABS ACOS ACS ANGLE ASC ASN ASIN ATN ATTR BIN BUMP CEIL CHECK CHR$ CODE COS COSH COT CSC DATE$ DEC DEG DIV DUP EPS ERR$ EXLINE EXOR EXP EXSTRING$ EXTYPE FN FP FRAC FRE FREE HEX$ IN INKEY INKEY$ INSERT INST INSTR INT IP JOY LBOUND LCASE$ LEFT$ LEN LN LOG LOG10 LOG2 LTRIM$ MAX MAXLEN MID$ MIN MOD ORD PEEK PEN PENX PENY PLACE POINT POINTER POS POT RAD RCLR RDOT REM RGB RGR RIGHT$ RLUM RND ROUND RSPCOLOR RSPPOS RSPRITE RTRIM$ RWINDOW SCREEN$ SEC SGN SIN SINH SIZE SPEEK SQR STR$ SYS TAN TANH TEST TIME$ TRUNCATE UBOUND UCASE$ USR VAL VAL$ WORD$ XOR
modifier 6: BRIGHT FLASH INK INVERSE OVER PAPER
operator 16: AND NOT OR + – * / ↑ ** = < > <= >= <> &
option 45: ATTRIBUTES BEAM BIAS BORDER CHARACTER COLOUR CURSOR CHARACTER CURSOR COLOUR DEFAULT CHANNEL EDITOR BUFFER EDITOR KEY EDITOR VIDEO FAST SAVE FKEY INK INTERRUPT CODE INTERRUPT KEY INTERRUPT NET INTERRUPT STOP KEY CLICK KEY DELAY KEY RATE LINE MODE LINE STYLE NET CHANNEL NET MACHINE NET NUMBER PALETTE PAPER REM1 REM2 SCROLL SERIAL BAUD SERIAL FORMAT SOUND BUFFER SOUND STYLE SPEAKER STATUS TAPE LEVEL TAPE SOUND TIMER VIDEO COLOUR VIDEO MODE VIDEO X VIDEO Y
reserved constant 9: BLACK BLUE CYAN GREEN INF MAGENTA RED WHITE YELLOW
reserved variable 11: DS DS$ EL ER ERRLN ERRN PI ST TI TI$ π
separator 6: : ; , ’ ( ) "
special function 4: AT BIN SPC TAB
statement 233: ALLOCATE ANGL APPEND ARC ASK BACKUP BANK BCKGNDS BEEP BEGIN BEND BFLASH BLOAD BLOCK BOOT BORDER BOX BRIGHT BSAVE CALL CAPTURE CAT CATALOG CAUSE CENTRE CGOTO CHAIN CHAR CIRCLE CLEAR CLOSE CLOSE# CLR CLS CMD CMOB CODE COLLECT COLLISION COLOR COLOUR CONCAT CONTINUE COPY CSET DATA DATE DCLEAR DCLOSE DEF DELAY DESIGN DETECT DIM DIR DIRECTORY DISABLE DISAPA DISK DISPLAY DISPLAY GRAPHICS DISPLAY TEXT DLOAD DO DOPEN DOWNB DOWNW DRAW DSAVE DUMP DVERIFY END END DEF END HANDLER END IF END LOOP END PROC END SELECT END WHEN ENVELOPE ERASE EXEC EXIT EXIT DEF EXIT DO EXIT FOR EXIT HANDLER EXIT IF EXT FAST FCHR FCOL FETCH FILL FILTER FIND FLASH FLUSH FOR FORMAT GET GETKEY GLOBAL GO GOSUB GOTO GRAPHIC GRAPHICS GSHAPE HANDLER HEADER HI COL HIRES HRDCPY IF IMAGE INFO INK INPUT INPUT# INV INVERSE KEY LEFTB LEFTW LET LINE LINE INPUT LLIST LOCAL LOCATE LOOK LOOP LOW COL LPRINT MEM MERGE MMOB MOB OFF MOB SET MOVE MOVSPR MULTI MUSIC NEW ALL NEXT NO ERROR NRM NUMERIC OFF ON ON ERROR ON KEY OPEN OPEN# OPTION ANGLE OUT OVER PAINT PAPER PAUSE PING PLAY PLOT POKE PRINT PRINT# PRINT USING PROC PROGRAM PUDEF RAND RANDOMIZE RCOMP READ REC RECORD REDIRECT REM RENAME REPEAT RESET RESTORE RESUME RETRACE RETRY RETURN RIGHTB RIGHTW RLOCMOB ROT SCALE SCNCLR SCRATCH SCRLD SCRSV SCROLL SELECT SET SLEEP SLOW SOUND SPOKE SPRCOLOR SPRITE SPRSAV SSHAPE START STASH STOP STRING SWAP TEMPO TEXT TIME TOGGLE TRACE TRAP TROFF TRON TYPE UNPLOT UNTIL UPB UPW USE VOL WAIT WAVE WHEN EXCEPTION USE WIDTH WINDOW @
symbol 10: B C "" # £ $ % ! ? .
DIALECTS
all 46: ABS AND ATN CHR$ COS EXP FOR GOSUB GOTO INT LEN LOG LOG10 LOG2 NEW NEXT NOT OR PEEK POKE RETURN SGN SIN SQR STEP STOP TAB TAN THEN TO VAL ; , + – * / = < > <= >= <> ( ) " $
all (exceptions below) 10: DIM IF INPUT LET LIST PRINT REM RND RUN STR$
all, except Sinclair 6: END LEFT$ MID$ RIGHT$ % ?
all, except Sinclair and Enterprise 1: ASC
all, except ZX81 4: DATA READ RESTORE :
C128 42: APPEND B BANK BEGIN BEND BLOAD BOOT BSAVE BUMP CATALOG COLLISION CONCAT DCLEAR DCLOSE DOPEN DVERIFY FAST FETCH FILTER MOVSPR P PEN PLAY POINTER POT RECORD RSPCOLOR RSPPOS RSPRITE RWINDOW SLEEP SLOW SPRCOLOR SPRDEF SPRITE SPRSAV STASH SWAP TEMPO WIDTH WINDOW XOR
Commodore 27: CLOSE CLR CMD CONT DEF FN FRE GET GO INPUT# LOAD ON OPEN POS PRINT# SAVE SPC ST SYS TI TI$ USR VERIFY WAIT ↑ # π
Enterprise 202: ACCESS ACOS ALL ALLOCATE ANGLE ASK ASIN AT ATTRIBUTE ATTRIBUTES AUTO BEAM BIAS BIN BLACK BLUE BORDER CALL CAPTURE CAUSE CEIL CHAIN CHARACTER CLEAR CLOSE CODE COLOR COLOUR CONTINUE COPY COSH COT CSC CURSOR CHARACTER CURSOR COLOUR CYAN DATE DATE$ DEF DEFAULT CHANNEL DEG DEGREES DELAY DELETE DISPLAY DISPLAY GRAPHICS DISPLAY TEXT DO DURATION EDIT EDITOR BUFFER EDITOR KEY EDITOR VIDEO END DEF END HANDLER END IF END SELECT END WHEN ENVELOPE EPS EXCEPTION EXIT DEF EXIT DO EXIT FOR EXIT HANDLER EXLINE EXSTRING$ EXT EXTYPE FAST SAVE FIRST FKEY FLUSH FP FREE FROM GET GRAPHICS GREEN HANDLER HEX$ HIRES IF MISSING IMAGE IN INF INFO INK INTERRUPT INTERRUPT CODE INTERRUPT KEY INTERRUPT NET INTERRUPT STOP IP JOY KEY CLICK KEY DELAY KEY RATE LAST LBOUND LCASE$ LINE INPUT LINE MODE LINE STYLE LLIST LOAD LOOK LOOP LORES LPRINT LTRIM$ MAGENTA MAX MAXLEN MERGE MIN NAME NET NET CHANNEL NET MACHINE NET NUMBER NEW ALL NUMBER NUMERIC OFF ON OPEN OPTION ANGLE ORD OUT PALETTE PAPER PING PITCH PLOT POS PROGRAM PROMPT RAD RADIANS RANDOMIZE READ RED REDIRECT RELEASE REM REM1 REM2 RENUMBER RETRY RGB RIGHT ROUND RTRIM$ SAVE SCROLL SEC SELECT SERIAL BAUD SERIAL FORMAT SET SINH SIZE SOUND SOUND BUFFER SOUND STYLE SOURCE SPEAKER SPEEK SPOKE START STATUS STR$ STRING STYLE SYNC TANH TAPE LEVEL TAPE SOUND TEXT TIME TIME$ TIMER TOGGLE TRACE TRUNCATE TYPE UBOUND UCASE$ VERIFY VIDEO COLOUR VIDEO MODE VIDEO X VIDEO Y WAIT WHEN EXCEPTION USE WHITE WORD$ YELLOW £ & !
Plus/4 59: AUTO BACKUP BOX CHAR CIRCLE COLLECT COLOR COPY D DEC DELETE DIRECTORY DLOAD DO DRAW DS DS$ DSAVE EL ELSE ER ERR$ EXIT GETKEY GRAPHIC GSHAPE HEADER HELP HEX$ I INSTR JOY KEY L LOCATE LOOP MONITOR PAINT PRINT USING PUDEF RCLR RDOT RENAME RENUMBER RESUME RGR RLUM SCALE SCNCLR SCRATCH SOUND SSHAPE TRAP TROFF TRON U UNTIL VOL WHILE
Simons 116: ANGL ARC AT AUTO B BCKGNDS BFLASH BLOCK C CALL CENTRE CGOTO CHAR CHECK CIRCLE CMOB COLD COLOUR COPY CSET DELAY DESIGN DETECT DIR DISABLE DISAPA DISK DISPLAY DIV DOWNB DOWNW DRAW DUMP DUP ELSE END LOOP END PROC ENVELOPE ERRLN ERRN EXEC EXIT IF EXOR FCHR FCOL FETCH FILL FIND FLASH FRAC GLOBAL HI COL HIRES HRDCPY INKEY INSERT INST INV JOY KEY LEFTB LEFTW LINE LOCAL LOOP LOW COL MEM MERGE MMOB MOB OFF MOB SET MOVE MULTI MUSIC NO ERROR NRM OFF OLD ON ERROR ON KEY OPTION OUT PAGE PAINT PENX PENY PLACE PLAY PLOT POT PROC RCOMP REC RENUMBER REPEAT RESET RESUME RETRACE RIGHTB RIGHTW RLOCMOB ROT SCRLD SCRSV SECURE TEST TEXT TRACE UNTIL UPB UPW USE VOL WAVE @ .
Simons Enterprise 1: MOD
Sinclair 13: ACS ASN AT CLEAR CLS CODE COPY LLIST LN LOAD LPRINT SAVE USR
Sinclair Enterprise 1: INKEY$
Spectrum 35: ATTR BEEP BIN BORDER BRIGHT CAT CIRCLE CLOSE# CONTINUE DEF DELETE DRAW ERASE FLASH FN FORMAT IN INK INVERSE LINE LOAD MERGE MOVE OPEN# OUT OVER PAPER PLOT POINT RANDOMIZE SAVE SCREEN$ VAL$ ’ ↑
Spectrum Enterprise 1: PI
ZX81 12: AT CONT FAST PAUSE PLOT RAND SCROLL SLOW UNPLOT ** "" π
TAGS
arithmetics 39: ABS BIN CEIL DEG DEGREES DIV EXP FP FRAC HEX$ INF INT IP LN LOG LOG10 LOG2 MAX MIN MOD OPTION ANGLE PI RAD RADIANS RAND RANDOMIZE REM RND SGN SQR TRUNCATE + – * / ↑ ** ( ) π
characters 1: @
clock 6: DATE DATE$ TI TI$ TIME$ TIMER
coding 23: AUTO CONT CONTINUE DELAY DELETE DISAPA FIND FIRST HELP LAST LIST MONITOR NEW NEW ALL OLD OPTION PAGE PROGRAM REM RENUMBER RUN SECURE START
colors 5: COLOR HI COL LOW COL MULTI RGB
errors 22: CAUSE EL ER ERR$ ERRLN ERRN EXCEPTION EXIT HANDLER EXLINE EXSTRING$ EXTYPE NO ERROR ON ERROR OUT RESUME RETRACE RETRY TRACE TRAP TROFF TRON WHEN EXCEPTION USE
execution 46: BEGIN BEND CALL CGOTO CHAIN DISABLE DO EDIT ELSE END END DEF END HANDLER END IF END LOOP END PROC END SELECT END WHEN EXEC EXIT EXIT DEF EXIT DO EXIT FOR EXIT IF FN FOR GO GOSUB GOTO IF LOOP NEXT ON PAUSE PROC RCOMP REPEAT RETURN SELECT SLEEP STOP SYS THEN UNTIL USR WAIT WHILE
files 20: APPEND BLOAD BOOT BSAVE CLOSE CONCAT COPY DCLOSE DIR DIRECTORY DLOAD DOPEN DSAVE DVERIFY MERGE OPEN RECORD SCRATCH SCRLD SCRSV
floppy 2: BACKUP COLLECT
graphics 50: ANGL ARC ATTR ATTRIBUTE ATTRIBUTES B BEAM BLOCK BOX BRIGHT C CHAR CIRCLE DISPLAY GRAPHICS DISPLAY TEXT DRAW FLASH GRAPHIC GSHAPE HIRES HRDCPY INK INVERSE LINE LINE MODE LINE STYLE LOCATE LOOK LORES MULTI OVER PAINT PAPER PLOT POINT RCLR RDOT REC RGR RLUM ROT SCALE SCNCLR SCREEN$ SSHAPE TEST TEXT UNPLOT WIDTH .
keyboard 14: DISPLAY FKEY GET GETKEY INKEY INKEY$ INTERRUPT KEY INTERRUPT STOP KEY KEY CLICK KEY DELAY KEY RATE ON KEY RESUME
logics 11: AND EXOR NOT OR XOR = < > <= >= <>
memory 15: ALLOCATE BANK CODE EPS FETCH FRE FREE MEM PEEK POINTER POKE SPEEK SPOKE STASH SWAP
network 6: INTERRUPT NET NET CHANNEL NET MACHINE NET NUMBER SERIAL BAUD SERIAL FORMAT
peripherals 52: ACCESS ALL B CAPTURE CAT CATALOG CLOSE# CMD D DCLEAR DELETE DISK DS DS$ EDITOR BUFFER EDITOR KEY EDITOR VIDEO ERASE FAST SAVE FLUSH FORMAT FROM GET HEADER I IN JOY L LOAD MOVE NAME ON OPEN# OUT P PEN PENX PENY POT PRINT# REDIRECT REM1 REM2 RENAME SAVE ST STEP TAPE LEVEL TAPE SOUND U VERIFY £
printing 3: COPY LLIST LPRINT
screen 62: AT BCKGNDS BFLASH BIAS BLACK BLUE BORDER CENTRE CHAR CHARACTER CLS COLOUR CSET CURSOR CHARACTER CURSOR COLOUR CYAN DESIGN DOWNB DOWNW FAST FCHR FCOL FILL GRAPHIC GREEN INV LEFTB LEFTW MAGENTA MOVE NRM OFF PALETTE POS PRINT PRINT USING PUDEF RCLR RED RIGHTB RIGHTW RLUM RWINDOW SCNCLR SCRLD SCRSV SCROLL SLOW SPC STATUS TAB TEXT UPB UPW USE VIDEO COLOUR VIDEO MODE VIDEO X VIDEO Y WHITE WINDOW YELLOW
sound 24: BEEP DURATION ENVELOPE FILTER INTERRUPT LCASE$ MUSIC NUMBER PING PITCH PLAY RELEASE RIGHT SOUND SOUND BUFFER SOUND STYLE SOURCE SPEAKER STYLE SYNC TAPE SOUND TEMPO VOL WAVE
sprites 18: BUMP CHECK CMOB COLLISION DETECT MMOB MOB OFF MOB SET MOVSPR RLOCMOB RSPCOLOR RSPPOS RSPRITE SPRCOLOR SPRDEF SPRITE SPRSAV @
strings 28: ASC CHR$ CODE DEC DUP INSERT INST INSTR LCASE$ LEFT$ LEN LTRIM$ MAXLEN MID$ ORD PLACE POS RIGHT$ ROUND RTRIM$ STR$ UCASE$ VAL VAL$ WORD$ " "" &
syntax 12: TO : ; , ’ = ( ) # $ % ! ?
system 11: ASK COLD DEFAULT CHANNEL EXT INFO INTERRUPT CODE NET SET TIME TOGGLE TYPE
trigonometry 15: ACOS ACS ANGLE ASN ASIN ATN COS COSH COT CSC SEC SIN SINH TAN TANH
variables 23: CLEAR CLR DATA DIM DUMP FETCH GLOBAL IF MISSING INPUT INPUT# LBOUND LET LINE LOCAL NUMERIC POINTER PROMPT READ RESET RESTORE SIZE STRING UBOUND