( Requires KBD_MEM, KBD_PORT )
( gm -- pm, get pressed keys mask for group mask gm )
CODE _get
    HL POPqq,
    chkPS,
    DI,
        A 0xff LDrn,
        KBD_PORT OUTnA,
        A L LDrr,
        KBD_PORT OUTnA,
        KBD_PORT INAn,
    EI,
    L A LDrr, HL PUSHqq,
;CODE