[Coco] os9/drivewire driver problems
aawolfe at gmail.com
Mon Nov 9 00:37:39 EST 2009
Just a note, my original code that pulled D and A from the stack at
the same time was a total mistake, due to my misunderstanding of..
well most everything :) I've got that sorted now.
On Mon, Nov 9, 2009 at 12:29 AM, Lothan <lothan at newsguy.com> wrote:
> Sheesh... I can't add today. You're right $04 + $02 is $06. I agree the
> other constructs don't make sense, but the result should be either logically
> OR'ing the register postbyte codes such that PULS A,B,D is the same as PULS
> D or PULS A,B (assuming it's just blindly picking through the
> comma-delimited register list) or raising an error that the list doesn't
> make any sense.
> From: "Robert Gault" <robert.gault at worldnet.att.net>
> Sent: Sunday, November 08, 2009 11:24 PM
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Subject: Re: [Coco] os9/drivewire driver problems
>> 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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