On Wednesday 21 June 2017, 19:27:48 Marko Mäkelä <email@example.com> wrote: > On Wed, Jun 21, 2017 at 04:40:03PM +0200, firstname.lastname@example.org wrote: > >According to the famous document by Chris Bauer, there are three timing > >variants of the VIC-II. While PAL is always 63 cycles per line, with > >NTSC there can be either 64 or 65 cycles per line and I am in fact able > >to reproduce the difference with -model ntsc and -model oldntsc in the > >current VICE. > > You should have the 6567R56A and 6567R8 that I gave you, right? > > >The question (before I spend weekend on trial'n error counting cycles > >and possibly reinventing the hammer ;-) is: do we have ane established, > >reliable software method for detecting which NTSC VIC-II is installed > >in the machine? I guess it must have been done multiple times by now > >and used in some NTSC games/demos.. > > The simple way is to disable interrupts and write a loop that samples > $d012, counting the cycles that go between changes. I do not know if > exactly such implementation is available anywhere. [snip] i wouldnt call that exactly simple :) counting cycles always needs to be cycle exact code - which is far from that. instead, simply check the number of scanlines - http://codebase64.org/doku.php?id=base:detect_pal_ntsc has a couple examples -- http://www.hitmen-console.org http://magicdisk.untergrund.net http://www.pokefinder.org http://ar.pokefinder.org Very few people do anything creative after the age of thirty-five. The reason is that very few people do anything creative before the age of thirty-five <Joel Hildebrand> Message was sent through the cbm-hackers mailing listReceived on 2017-06-21 17:05:10
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