This is an adaptation of the 6502js project from https://github.com/skilldrick/6502js which has been added to this website for cloud based 6502 assembler programming.
Notes: Memory location $fe contains a new random byte on every instruction. Memory location $ff contains the ascii code of the last key pressed, $0d is Enter, $08 is backspace. Memory locations $200 to $5ff map to the screen pixels. Different values will draw different colour pixels. The colours are: $0: Black $1: White $2: Red $3: Cyan $4: Purple $5: Green $6: Blue $7: Yellow $8: Orange $9: Brown $a: Light red $b: Dark grey $c: Grey $d: Light green $e: Light blue $f: Light grey Reference: 6502.org (preferred) Obelisk Easy 6502 Assembly in One Step 6502 Adressing Modes 6502 Registers Addressing: ZP, X - ZP = $80 ; X = $0F ; Result = $8F ZP, Y - ZP = $80 ; Y = $0F ; Result = $8F ABSO, X - ABSO = $2000 ; X = $92 ; Result = $2092 ABSO, Y - ABSO = $2000 ; Y = $92 ; Result = $2092 (ABSO) - ABSO = $2000 ; Result = address @ location $2000 (ZP, X) - ZP = $80 ; X = $0F ; Result = (address @ location $80 + $0F) (ZP), Y - ZP = $80 ; Y = $0F ; Result = address @ location $80 + $0F