commodong 4096

Instructions

simple 8bit cpu with display press button to turn on runs best with turbowarp https://turbowarp.org/1374382591 zeropage: 0-255 program loads at 256 stack at 60928-61183 sound at 61437 (a little slow, might get your program stuck if not given enough waiting time) input (space key) at 61438 scanline at 61439 vram at 61440-65535 opcodes: 0 - no operation (0 args) 1 - load memory from address at accumulator (2 args) 2 - load memory from address at x register (2 args) 3 - load memory from address at y register (2 args) 4 - load value to accumulator (1 arg) 5 - load value to x register (1 arg) 6 - load value to y register (1 arg) 7 - store accumulator at address (2 args) 8 - store x register at address (2 args) 9 - store y register at address (2 args) 10 - jump to address (2 args) 11 - increment memory at address (2 args) 12 - increment x register (0 args) 13 - increment y register (0 args) 14 - decrement memory at address (2 args) 15 - decrement x register (0 args) 16 - decrement y register (0 args) 17 - add value to accumulator (1 arg) 18 - add accumulator to memory at address (2 args) 19 - subtract value from accumulator (1 arg) 20 - subtract accumulator from memory at address (2 args) 21 - clear carry flag (0 args) 22 - set carry flag (0 args) 23 - compare accumulator to memory at address (2 args) 24 - compare accumulator to value (1 arg) 25 - compare x register to value (1 arg) 26 - compare y register to value (1 arg) 27 - branch on equal (2 args) 28 - branch on not equal (2 args) 29 - branch on carry set (2 args) 30 - branch on carry clear (2 args) 31 - store accumulator at address (x indexed) (2 args) 32 - store accumulator at address (y indexed) (2 args) 33 - load memory from address at accumulator (x indexed) (2 args) 34 - load memory from address at accumulator (y indexed) (2 args) 35 - store accumulator at address (x indexed indirect) (1 args) 36 - store accumulator at address (y indirect indexed) (1 args) 37 - load memory from address at accumulator (x indexed indirect) (1 args) 38 - load memory from address at accumulator (y indirect indexed) (1 args) 39 - jump to subroutine (2 args) 40 - return from subroutine (0 args) 41 - push to stack (0 args) 42 - pull from stack (0 args) 43 - transfer x register to accumulator (0 args) 44 - transfer accumulator to x register (0 args) 45 - transfer y register to accumulator (0 args) 46 - transfer accumulator to y register (0 args) 47 - shift memory at address left (2 args) 48 - shift memory at address right (2 args) 49 - shift accumulator left (0 args) 50 - shift accumulator right (0 args)

Notes & Credits