collapseos/blk/321

    BEGIN, ( loop )
        SCF,
        C RL,
        RLA,
        HL ADCHLd,
        DE SBCHLd,
        IFC,
            DE ADDHLd,
            C DECr,
        THEN,
    DJNZ, AGAIN, ( loop )
    B A LDrr,
    HL PUSH,
    BC PUSH,
;CODE