csrand_init:
; ix = selected byte
; de = current deviation
; hl = starting address
; bc = bytes to check
; outputs: hl = address
    push ix
        ld ix, 0
        ld de, _max_deviation
        ld hl, $D65800
        ld bc, 513
.test_range_loop:
        push bc
            push hl
                call _test_byte
            pop hl
        pop bc
        inc hl
        dec bc
        ld a,c
        or a,b
        jq nz,.test_range_loop
        push ix
        pop hl
        ld (_sprng_read_addr), hl
        add hl, de
        sbc hl, de
        jr nc, .retzero
        ld a, 1
        jr .return
.retzero:
        xor a
.return
    pop ix
    ret