A very convenient feature of Commodore's ROM-resident BASIC interpreter and KERNAL was the brilliantly implemented full screen editor, which allowed users to input, edit, and enter direct commands as well as program lines anywhere on the screen – simply by pressing the RETURN
key whenever the cursor happened to be on a line containing a valid BASIC statement. This marked a huge leap forward in program entry interfaces compared to other common home computer BASICs at the time, which typically used a separate EDIT
command for line editing.
Versions (in chronological order, with successively added features)
PEEK
command won't work above memory location $C000 WAIT 6502,
and see what happens...DLOAD,DSAVE,COPY,SCRATCH,
etc (15 in all)
DS,DS$
JOY
DEC(),HEX$()
RESTORE [linenumber]
INSTR
PRINT USING,PUDEF
ELSE
DO,LOOP,WHILE,UNTIL,EXIT
KEY
AUTO,DELETE,RENUMBER
TRAP,RESUME,ERR$()
TRON,TROFF
POT,PEN
XOR
POINTER
WINDOW
SLEEP
BANK,STASH,FETCH,SWAP
BOOT,BLOAD,BSAVE,DVERIFY,DCLEAR
RREG
(read CPU registers after a SYS
)
OFF,QUIT