# Chip8 is a virtual machine designed in 1977 for programming video games.
# Octo is a high level assembler, disassembler and simulator for Chip8.
# Click 'Run' and then press ASWD to move the sprite around the screen.
# Click the Octo logo for source, documentation and examples.

:alias px v1
:alias py v2

: main
  px := random 0b0011111
  py := random 0b0001111
  i  := person
  sprite px py 8

  loop
    # erase the player, update its position and then redraw:
    sprite px py 8
    v0 := OCTO_KEY_W if v0 key then py += -1
    v0 := OCTO_KEY_S if v0 key then py +=  1
    v0 := OCTO_KEY_A if v0 key then px += -1
    v0 := OCTO_KEY_D if v0 key then px +=  1
    sprite px py 8

    # lock the framerate of this program via the delay timer:
    loop
      vf := delay
      if vf != 0 then
    again
    vf := 3
    delay := vf
  again

: person
  0x70 0x70 0x20 0x70 0xA8 0x20 0x50 0x50