EclaireXL

06/21/2018

FO 09:44 PM Bug #67: Pokey two tone timing problem

I found if I pokey 53775,11+128 on the Atari then it matches the Eclaire output. Unfortunately forcing the serious output on eclaire to 1 or 0 does not change anything. Still its something to go on! foft

06/20/2018

FO 10:03 PM Bug #67: Pokey two tone timing problem

So, errr identical then! Going to have to think about this one...
B is Atari, A is EclaireXL.
!http://www.64kib.com/redmine/attachments/download/82/Screenshot%20from%202018-06-20%2023-02-19.png!
foft

FO 09:57 PM Bug #67: Pokey two tone timing problem

Nope, seems to be some interaction with the noise filtering. I wonder if the delay also needs applying to the pulse from the timer, that then hits the noise filter. foft

FO 09:27 PM Bug #67: Pokey two tone timing problem

A 2 cycle delay on the reset fixes both the 4 cycle and the 9 cycle case.
Now to check this specific example! foft

06/19/2018

FO 09:55 PM Bug #67: Pokey two tone timing problem

I was concerned that my clocks were off at first since I was running in VGA mode, but that changes vsync slightly (50Hz vs 4.86Hz) which of course also impacts audio frequency:-) Debugging in RGB mode gives a perfect match. foft

FO 09:54 PM Bug #67: Pokey two tone timing problem

Been measuring cases on the scope...
Confirmed the extra cycle delays described in that forum post on my 600XL. Confirmed missing on the EclaireXL implementation. foft

06/14/2018

FO 08:35 PM Bug #67: Pokey two tone timing problem

Related post: http://atariage.com/forums/topic/118448-implementation-of-pokey-2-tone-filter-in-emulation/page-3#entry1449990 foft