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 attributesMMOB – positions a sprite on the screenRLOCMOB – causes a sprite to smoothly move from one location to anotherCMOB – sets up the two global colours for multicolour spritesMOB OFF – disables a spriteDETECT – initializes sprite collision detectionCHECK – checks for a sprite collisionHigh resolution graphics handling keywords
HIRES – initializes a high-resolution graphics modeMULTI – initializes a multicolour graphics modeNRM – returns to the text displayLOW COL – changes the plotting coloursHI COL – returns to the original plotting coloursPLOT – draws a pixelLINE – draws a lineCIRCLE – draws a circleARC – draws an arcANGL – draws the radius of a circlePAINT – performs a flood fillREC – draws a hollow rectangleBLOCK – draws a solid rectangleDRAW – draws a user-defined set of linesROT – sets scaling factors for DRAWCHAR – plots a text character on a high-resolution screenTEXT – plots a text string on a high-resolution screenTEST – determines whether a pixel is plotted or emptyOther graphics handling keywords
COLOUR – sets the background and border coloursCSET – selects a character setMEM – copies character ROM to RAMBCKGNDS – configures extended background colour modeFLASH – sets up a screen colour to flashOFF – cancels a previous FLASH directiveBFLASH – causes the screen border to flashFCHR – fills an area of the text screen with a given character codeFCOL – changes character colours for a selected area of the screenFILL – a combination of FCHR and FCOLMOVE – copies a section of the screenINV – displays a screen area in reverseLEFT – scrolls the screen leftRIGHT – scrolls the screen rightUP – scrolls the screen upDOWN – scrolls the screen downGRAPHICS – 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 variablePLAY – determines whether the program continues to run during MUSICVOL – specifies the master sound volumeWAVE – specifies a voice typeENVELOPE – sets ADSR parameters for a SID voiceSOUND – reserved variable that always equals $D400 (the SID chip's base address)FETCH – takes user input with restrictions defined by the commandINKEY – checks for a function key pressON KEY – checks for a given keypress, then performs a branch if presentDISABLE – disables the previous ON KEY directiveRESUME – reenables the previous ON KEY directiveJOY – reads a joystickPOT – reads a paddlePENX – reads the light pen's horizontal positionPENY – reads the light pen's vertical position@ – describes one line in a sprite or custom character graphicDESIGN – uses neighbouring @ lines to define a sprite or custom characterON ERROR – sets up a routine to trap error conditionsOUT – ends an error handling routineNO ERROR – cancels ON ERROR and restores normal BASIC error handlingDisk handling keywords
DIR – displays the disk directory without destroying the BASIC program in memoryDISK – sends a string to the disk drive's command channelSCRSV – saves a text screen to diskSCRLD – loads a text screen from diskPrinter handling keywords
HRDCPY – sends the text screen to the printerCOPY – sends the high-resolution screen to the printerINSERT – inserts one string into the middle of anotherINST – similar to INSERT, but overwrites rather than insertingPLACE – searches for one string in the middle of anotherDUP – duplicates a character string a given number of timesAT – prints a string at a given screen locationCENTRE – centres a character string on the screenUSE – formats numeric data in strings based on a templateLIN – returns the vertical position of the cursorMOD – performs a division operation and returns the remainderDIV – performs a division operation and returns the integer quotientFRAC – isolates the fractional portion of a numberEXOR – performs an exclusive-OR logical operationAUTO – automatically generates line numbers as a BASIC program is enteredRENUMBER – renumbers a BASIC program (but does not fix GOTO/GOSUB statements)OLD – undeletes a program accidentally removed by the NEW commandKEY – assigns a string as a macro to a function keyDISPLAY – displays all function key macrosMERGE – merges a BASIC program from disk into the program currently in memoryPAGE – displays a BASIC program listing in page formatOPTION – highlights Simons' BASIC keywords when using the LIST commandDELAY – varies the rate at which the LIST command scrolls the screenFIND – searches the program for a stringTRACE – displays the line numbers as a program is runningRETRACE – displays results of a traceDUMP – displays all variable values except for arraysCOLD – resets the C64DISAPA – marks a BASIC program line for hidingSECURE – hides all lines marked with DISAPA so that they cannot be viewed with LISTELSE – allows an alternative branch for IF/THEN conditionalsREPEAT – start of a REPEAT/UNTIL loop structureUNTIL – defines the loop condition for a REPEAT/UNTIL loop structure, and marks its endRCOMP – recapitulates the last IF/THEN conditionalLOOP – defines the start of a loop that will run until an EXIT IF conditional is trueEXIT IF – the conditional is true, so it exits the current LOOP/END LOOP structureEND LOOP – defines the end of a loop that will run until an EXIT IF conditional is truePROC – defines the start of a named subroutineEND PROC – defines the end of a named subroutineCALL – jump to a named subroutine defined with PROC/END PROC, and stay thereEXEC – call a named subroutine defined with PROC/END PROC, then returnLOCAL – redefines variables for use in structuresGLOBAL – reverses the effects of a previous LOCAL commandCGOTO – equivalent to GOTO, but accepts calculated expressionsRESET – moves the DATA pointer to a given line numberPAUSE – 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."
