hi guys. thanks for the help.

below if my full final code which seems to work.
i added 4 button sensors on A inputs 0-3 which choose a tune to play.




SETVAL: SET TEMPX=$00
SET TEMPY=$01
SET PAUSEX=$02
SET PAUSEY=$03
SET NOTENUM=$04
SET TUNENUM=$05

SET VIAT1L=$4004 ; via timer 1 ...

Thanks for your help.

I have had a look into using timer 1 and PB7. The datasheed has the essential info but its not too well documented elsewhere.

i have written this code....


ORG $F800
SETVAL: SET TEMPY=$00
SET TEMPX=$00
SET PAUSEX=$50 ;PAUSEX/Y set to 50k cycles
SET PAUSEY=$C3
SET ...

Im working on a project that uses a 6522 VIA to create a square wave.

I have been told by setting the shift register on the via to 10101010 i can generate a continous square wave on the CB2 pin. However i am having trouble and my program does not seem to work.

i have come accross limited resources ...