collapseos/blk/624

CODE _blank ( this is way too slow in Forth )
    A XORr, VDP_CTLPORT OUTiA,
    A 0x40 LDri, VDP_CTLPORT OUTiA,
    HL 0x4000 LDdi,
    BEGIN,
        A XORr, VDP_DATAPORT OUTiA,
        HL DECd, HLZ,
    JRNZ, AGAIN,
;CODE