[Coco] Apparent discrepancy between MAME and XRoar re: SBCB instruction

[tim lindner]

Hey Ron. Yeah, I'll come and go at times. :)

I posted the email from Pierre to #mame-dev. I see the fix has already
been merged.

On Wed, Oct 18, 2017 at 4:35 PM, Ron Klein <ron at kdomain.org> wrote:
> Hi Tim,
>
> Great to see you are still around!  I was asking Boisy about you at Tandy
> Assembly.  In any case, did you submit the your findings to mametesters?
>
> Thanks
>
> -Ron
>
>
> On Tue, Oct 17, 2017 at 7:40 PM, tim lindner <tlindner at macmess.org> wrote:
>
>> On Tue, Oct 17, 2017 at 4:22 PM, Pierre Sarrazin <sarrazip at sarrazip.com>
>> wrote:
>> > On MAME 0.158, it's 7 while on XRoar, it's 5.
>>
>> Here is the code in MASTER branch of MAME:
>>
>> SBC8:
>> m_temp.w = (uint16_t)read_operand() + (m_cc & CC_C ? 1 : 0);
>> regop8() = set_flags(CC_NZVC, regop8(), m_temp.b.l, regop8() - m_temp.w);
>> return;
>>
>>
>> Operand plus carry? It seems you found a legitimate bug.
>>
>>
>>
>> <https://github.com/mamedev/mame/blob/master/src/devices/
>> cpu/m6809/base6x09.ops#L241>
>>
>> --
>> --
>> tim lindner
>>
>> "Proper User Policy apparently means Simon Says."
>>
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>>
>
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-- 
--
tim lindner

"Proper User Policy apparently means Simon Says."