DCPU-16 Emulator

This is a DCPU-16 emulator. The DCPU-16 was a theoretical MISC cpu arch designed for a game ("0x10c") that got a lot of hype but (I think) never saw the day of light. I was enthousiastic about this game too and when a spec was released for an ingame CPU I wanted to create an emulator for it. So that's what this is.

By Peter van der Zee, © pvdz.ee, April 2012. See code on GitHub.

	A	B	C	X	Y	Z	I	J	PC	SP	EX	IA
dec
hex

Keyboard input registers:

;start at [0x9010]+1
;find first non-zero index
;that's the next keyboard input
;if not found after 16 tests, fail and repeat
;else, log, clear and repeat

jsr getc
brk 0

:memcopy ; I:source, J:target, clobbers: I&J
  sti [J], [I]
  sti [J], [I]
  sti [J], [I]
  sti [J], [I]
  sti [J], [I]
  sti [J], [I]
  sti [J], [I]
  sti [J], [I]
  sti [J], [I]
  sti [J], [I]
  sti [J], [I]
  set pc, pop

:getc
                      ; copy keyboard buffer first
  set i, 0x9000       ; start of source
  set j, 0x9011       ; start of target
  jsr memcopy

set a, [0x9021]   ; a is adr of last key (loop starts after it)
  add a, 0x11       ; adjust for cached buffer
  set i, 0          ; init counter
  :while
    add a, 1        ; get next buf pos
    ifg a, 0x9020   ; if a is beyond buffer
     set a, 0x9011  ; reset a to start of buffer
    set b, [a]      ; get key value of current index
    ifn b, 0        ; if non-zero, we found something
      set pc, found
    add i, 1        ; only check 16 inputs
    ifg i, 0xf      ; after whole buf, fail
      set pc, getc  ; and repeat
    set pc, while   ; else, repeat

:found
  log b
  sub a, 0x11       ; target real buffer
  set [a], 0        ; "mark" key as read
  set pc, pop