Home > CBM > BASIC > Keywords > On
180 Subpages: (divide), (equal), (less), (minus), (more), (multiply), (plus), (power), Abs, And, Append, Asc, Atn, Auto, Backup, Bank, Begin, Bend, Bload, Boot, Box, Bsave, Bump, Catalog, Char, Chr, Circle, Close, Clr, Cmd, Collect, Collision, Color, Concat, Cont, Copy, Cos, Data, Dclear, Dclose, Dec, Def, Delete, Dim, Directory, Dispose, Dload, Do, Dopen, Draw, Ds, Ds string, Dsave, Dverify, El, Else, End, Envelope, Er, Err, Exit, Exp, Fast, Fetch, Filter, Fn, For, Fre, Get, Get num, Getkey, Go, Gosub, Goto, Graphic, Gshape, Header, Help, Hex, If, Input, Input num, Instr, Int, Joy, Key, Left, Len, Let, List, Load, Locate, Log, Loop, Mid, Monitor, Movspr, New, Next, Not, Off, Open, Or, Paint, Peek, Pen, Pi, Play, Pointer, Poke, Pos, Pot, Print, Print num, Pudef, Quit, Rclr, Rdot, Read, Record, Rem, Rename, Renumber, Restore, Resume, Return, Rgr, Right, Rlum, Rnd, Rreg, Rspcolor, Rsppos, Rsprite, Run, Rwindow, Save, Scale, Scnclr, Scratch, Sgn, Sin, Sleep, Slow, Sound, Spc, Sprcolor, Sprdef, Sprite, Sprsav, Sqr, Sshape, St, Stash, Step, Stop, Str, Swap, Sys, Tab, Tan, Tempo, Then, Ti, Ti string, To, Trap, Troff, Tron, Until, Using, Usr, Val, Verify, Vol, Wait, While, Width, Window, Xor

KeywordAbbreviationToken (hex)Version(s)Classification
ONnone911.0+Preposition

Syntax 
[ ON selector ] { GOSUB | GOTO } lineNumber [ , lineNumber ] ...
 ~ or ~
KEY [ { ON | OFF | key_number [ , definition ] } ]
 ~ or ~
{ APPEND | BACKUP | BOOT | BLOAD | BSAVE | CATALOG | COLLECT | CONCAT | COPY | DIRECTORY | DLOAD | DSAVE | DVERIFY | HEADER RENAME | RUN | SCRATCH } [ parameter ]... [ { , | ON } U device_number ] [ parameter ]...
 
 
Purpose 
Influence the behavior of other statements/commands.

 
 
Remarks 
The use of ON/OFF with the KEY command seems to be from the unreleased Commodore LCD.  Remnants of this code can be found in the BASIC 7.0 ROMs of the Commodore 128; however such use doesn't function in v7.0. 

It's main use is to select one of many program lines (a switch statement in other languages) using either GOTO or GOSUB.

Example:
10 INPUT N
20 ON N GOTO 100, 200, 300
30 STOP
100 PRINT 1 : END
200 PRINT 2 : END
300 PRINT 3 : END
 
With the disk-related commands (DLOAD and friends), the ON preposition appears to perform the same task as a comma: to seperate items in a list.  However the ON keyword may be used where a comma would generate a SYNTAX ERROR.  Very hard to describe, so here are some examples!
DIRECTORY "*" , U8
0 "SAMPLE DISK     " H2 2A
664 BLOCKS FREE

READY.
DIRECTORY "*" ON U8
0 "SAMPLE DISK     " H2 2A
664 BLOCKS FREE

READY.
DIRECTORY , U8

?SYNTAX ERROR
READY.
DIRECTORY ON U8
0 "SAMPLE DISK     " H2 2A
664 BLOCKS FREE

READY.

Compare With 

Contrast With 
OFF 

See Also 

© H2Obsession, 2014