sand asm random side routine

    push hl
    ld a, 0
    call random
    bit 0, l
    jp z, randzero
    ld a, 1
    jp randone
randzero:
    ld a, 0
randone:
    add a, a
    ld c, a
    ld b, 0
    ld hl, 319
    add hl, bc
    ex de, hl
    pop hl \ push hl ; update hl
    add hl, de
    ld a, (hl)
    cp a, 1
    jp z, tryotherside
    cp a, 2
    jp z, tryotherside
    pop hl
    add hl, de
    jp cantMoveDown
tryotherside:
    ld hl, 321
    xor a
    sbc hl, bc
    ex de, hl
    pop hl \ push hl
    add hl, de
    ld a, (hl)
    cp a, 1
    jp z, cantMoveDown
    cp a, 2
    jp z, cantMoveDown
    pop hl
    add hl, de
    jp canMoveDown