[Coco] os9/drivewire driver problems

Robert Gault robert.gault at worldnet.att.net
Sun Nov 8 23:24:30 EST 2009


Lothan wrote:
> Given the layout of the register postbyte, PULS A,B is exactly the same
> as PULS D (e.g. the postbyte is $05 in either case), so PULS A,D and
> PULS B,D and PULS A,B,D should in theory all compile exactly the same as
> PULS A,B or PULS D.
>
> Someone feel free to smack me with a clue stick if I have that wrong.

No smack, but you might consider this.

PULS A,B and PULS D both give $35 $06. So, the post byte is 6 not 5. The 
other constructs don't make any sense and a good assembler should report 
an error. After all, you are asking for an ambiguous action. What values 
are going to be put in regs A & B if you ask for PULS A,D?

EDTASM gives Register Error for a multiple pull/push of the same register.



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