|
Post by VDC 8x2 on Oct 8, 2016 0:55:52 GMT
Some code to write data to vdc registers in pairs or single.
X is the register number A holds low byte or single byte
In the pair code, Y holds the high byte of the register pair. X is incremented for the second of the reg pair.
VDCADR = $d600 VDCDAT = $d601
ldaVDC stx VDCADR @loop bit VDCADR bpl @loop lda VDCDAT rts
ldaVDCp stx VDCADR @loop bit VDCADR bpl @loop ldy VDCDAT inx stx VDCADR lda VDCDAT rts
staVDC stx VDCADR @loop bit VDCADR bpl @loop sta VDCDAT rts staVDCp stx VDCADR @loop bit VDCADR bpl @loop sty VDCDAT inx stx VDCADR sta VDCDAT rts
|
|