Simons' BASIC added 114 additional keywords to BASIC 2.0. These included commands to ease the coding of sprites, high-resolution and multicolour graphics, and sound. In addition, commands were also implemented to aid in structured programming. Keywords to assist in writing and editing BASIC programs, similar to those in the VIC-20 Programmer's Aid cartridge, were also included. Also, programs written in Simons' BASIC could employ hexadecimal numbers in assignments and calculations by including a $ prefix, or binary numbers by utilizing a % prefix.
Because a portion of the cartridge data was mapped into memory at addresses $8000–$9FFF, which overlapped part of the standard C64 BASIC RAM, the amount of available memory for BASIC programs was 8 KB less than that of a standard C64 configuration.
A further extension to the Commodore V2 Basic was also written by Simons and released by Commodore on floppy disk as Simons' Basic 2. It could not be released on cartridge because the original Simons' Basic cartridge had to be present in order to use the extension. Simons' Basic 2 added 91 extra commands including a much coveted RENUMber command which also took care of renumbering the destinations of GOTO and GOSUB statements.
Sprite (MOB) handling keywords
MOB SET – enables a sprite and defines its attributes
MMOB – positions a sprite on the screen
RLOCMOB – causes a sprite to smoothly move from one location to another
CMOB – sets up the two global colours for multicolour sprites
MOB OFF – disables a sprite
DETECT – initializes sprite collision detection
CHECK – checks for a sprite collision
High resolution graphics handling keywords
HIRES – initializes a high-resolution graphics mode
MULTI – initializes a multicolour graphics mode
NRM – returns to the text display
LOW COL – changes the plotting colours
HI COL – returns to the original plotting colours
PLOT – draws a pixel
LINE – draws a line
CIRCLE – draws a circle
ARC – draws an arc
ANGL – draws the radius of a circle
PAINT – performs a flood fill
REC – draws a hollow rectangle
BLOCK – draws a solid rectangle
DRAW – draws a user-defined set of lines
ROT – sets scaling factors for DRAW
CHAR – plots a text character on a high-resolution screen
TEXT – plots a text string on a high-resolution screen
TEST – determines whether a pixel is plotted or empty
Other graphics handling keywords
COLOUR – sets the background and border colours
CSET – selects a character set
MEM – copies character ROM to RAM
BCKGNDS – configures extended background colour mode
FLASH – sets up a screen colour to flash
OFF – cancels a previous FLASH directive
BFLASH – causes the screen border to flash
FCHR – fills an area of the text screen with a given character code
FCOL – changes character colours for a selected area of the screen
FILL – a combination of FCHR and FCOL
MOVE – copies a section of the screen
INV – displays a screen area in reverse
LEFT – scrolls the screen left
RIGHT – scrolls the screen right
UP – scrolls the screen up
DOWN – scrolls the screen down
GRAPHICS – reserved variable that always equals $D000 (the VIC-II chip's base address)
Sound handling keywords
MUSIC – plays a series of notes based on the contents of a string variable
PLAY – determines whether the program continues to run during MUSIC
VOL – specifies the master sound volume
WAVE – specifies a voice type
ENVELOPE – sets ADSR parameters for a SID voice
SOUND – reserved variable that always equals $D400 (the SID chip's base address)
FETCH – takes user input with restrictions defined by the command
INKEY – checks for a function key press
ON KEY – checks for a given keypress, then performs a branch if present
DISABLE – disables the previous ON KEY directive
RESUME – reenables the previous ON KEY directive
JOY – reads a joystick
POT – reads a paddle
PENX – reads the light pen's horizontal position
PENY – reads the light pen's vertical position
@ – describes one line in a sprite or custom character graphic
DESIGN – uses neighbouring @ lines to define a sprite or custom character
ON ERROR – sets up a routine to trap error conditions
OUT – ends an error handling routine
NO ERROR – cancels ON ERROR and restores normal BASIC error handling
Disk handling keywords
DIR – displays the disk directory without destroying the BASIC program in memory
DISK – sends a string to the disk drive's command channel
SCRSV – saves a text screen to disk
SCRLD – loads a text screen from disk
Printer handling keywords
HRDCPY – sends the text screen to the printer
COPY – sends the high-resolution screen to the printer
INSERT – inserts one string into the middle of another
INST – similar to INSERT, but overwrites rather than inserting
PLACE – searches for one string in the middle of another
DUP – duplicates a character string a given number of times
AT – prints a string at a given screen location
CENTRE – centres a character string on the screen
USE – formats numeric data in strings based on a template
LIN – returns the vertical position of the cursor
MOD – performs a division operation and returns the remainder
DIV – performs a division operation and returns the integer quotient
FRAC – isolates the fractional portion of a number
EXOR – performs an exclusive-OR logical operation
AUTO – automatically generates line numbers as a BASIC program is entered
RENUMBER – renumbers a BASIC program (but does not fix GOTO/GOSUB statements)
OLD – undeletes a program accidentally removed by the NEW command
KEY – assigns a string as a macro to a function key
DISPLAY – displays all function key macros
MERGE – merges a BASIC program from disk into the program currently in memory
PAGE – displays a BASIC program listing in page format
OPTION – highlights Simons' BASIC keywords when using the LIST command
DELAY – varies the rate at which the LIST command scrolls the screen
FIND – searches the program for a string
TRACE – displays the line numbers as a program is running
RETRACE – displays results of a trace
DUMP – displays all variable values except for arrays
COLD – resets the C64
DISAPA – marks a BASIC program line for hiding
SECURE – hides all lines marked with DISAPA so that they cannot be viewed with LIST
ELSE – allows an alternative branch for IF/THEN conditionals
REPEAT – start of a REPEAT/UNTIL loop structure
UNTIL – defines the loop condition for a REPEAT/UNTIL loop structure, and marks its end
RCOMP – recapitulates the last IF/THEN conditional
LOOP – defines the start of a loop that will run until an EXIT IF conditional is true
EXIT IF – the conditional is true, so it exits the current LOOP/END LOOP structure
END LOOP – defines the end of a loop that will run until an EXIT IF conditional is true
PROC – defines the start of a named subroutine
END PROC – defines the end of a named subroutine
CALL – jump to a named subroutine defined with PROC/END PROC, and stay there
EXEC – call a named subroutine defined with PROC/END PROC, then return
LOCAL – redefines variables for use in structures
GLOBAL – reverses the effects of a previous LOCAL command
CGOTO – equivalent to GOTO, but accepts calculated expressions
RESET – moves the DATA pointer to a given line number
PAUSE – pauses program execution for a specified number of seconds
$ and % are also considered keywords, for a total of 114.
The band Barcelona titled their 1999 debut album Simon Basic in tribute. The album includes the song "C-64".
Creative Computing stated that Simons' BASIC "almost makes the 64 into a new computer. (Probably the one it should have been in the first place.)" It praised the "very fine manual" as a contrast to Commodore's usually poor documentation, and predicted that it would become "the standard language for programming the machine … Commodore had better be planning to manufacture lots of copies because they will go fast". Ahoy! wrote "If you do any programming in BASIC and should happen to see this product on a dealer's shelf, do not ask any questions—do not hesitate—just buy it!" The magazine praised Simons' BASIC's power and "excellent manual", and stated that "its price makes it one of the biggest bargains available for the Commodore 64". RUN's review was less favorable, stating that its "many powerful and useful commands … were, unfortunately, implemented very poorly for a commercial package. There is very little command parameter checking, and many things have been overlooked or ignored."
