CODE LSHIFT ( n u -- n )
    BC POPqq, ( u )
    HL POPqq, ( n )
    chkPS,
    B C LDrr,
    B INCr, B DECr, IFNZ,
        BEGIN,
            L SLAr, H RLr,
        DJNZ, AGAIN,
    THEN,
    HL PUSHqq,
;CODE