Quick Reference

Disassemble from Address

.addr ; Official 6502 instructions
,addr ; Plus Undocumented instructions

Assemble at Address

@addr mne [operand]
@addr "string"
@addr:nn [nn] [nn] [nn]
@addr%bbbbbbbb

Symbol Management

*addr ; Set persistent counter
*     ; Show symbol table
*-    ; Clear symbol table

Memory Dump

:addr ; Hex
%addr ; Binary

Register Management

;    ; Display registers
;ac [xr] [yr] [pr]

Execute Subroutine

<-addr ; Left-arrow
<-     ; Continue after BRK

Note <- means the left-pointing arrow on the VIC-20's keyboard, the one in the upper left-hand corner.

Breakpoint Management

!addr        ; Set breakpoint, enable BRK trapping
!            ; Clear breakpoint, enable BRK trapping
Stop/Restore ; Disable BRK trapping

Memory Save/Load

>start end+1 ["filename"] ; Save
<["filename"]             ; Load

Copy and Pattern Fill

&start end target ; Copy
@start "pattern"  ; Pattern Fill
&start end *      ; ,,

Search

/addr:nn [nn] [nn] [nn] [nn] [nn] [nn] [nn]
/addr "string" ; Up to 16 characters
/addr mne [operand]

Assertion Tester

=addr nn [nn] [nn] [nn] [nn] [nn] [nn] [nn]

Numeric Conversion

$hh[hh]  ; Hex to base-10
#number  ; Base-10 to Hex

BASIC Stage

^start-page [end-page] [NEW]  ; Set stage address
^                             ; Show stage address

Note ^ means the up-pointing arrow on the VIC-20's keyboard.