Binary counter

VAR step
VAR counter
VAR tmp
VAR tmp2

EXT cube1
EXT cube2
EXT cube3
EXT cube4

PC step

LOOP:
    ADD counter, #1
    MOD counter, #16
    LD tmp, counter

    MOD tmp, #2 => tmp2
    LD cube1, tmp2
    DIV tmp, #2

    MOD tmp, #2 => tmp2
    LD cube2, tmp2
    DIV tmp, #2

    MOD tmp, #2 => tmp2
    LD cube3, tmp2
    DIV tmp, #2

    MOD tmp, #2 => tmp2
    LD cube4, tmp2

    BR LOOP