> On 2017-06-21, at 17:01, groepaz@gmx.net 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. >> >> 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.. > > most demos or games probably dont care about detecting the difference - as the > 64 cycle VIC is extremely rare. Maybe I am impractical indeed, yet I can't envision a commercial product (game f.e.) that would just break because the machine has a different but still valid VIC chip inside. > however, iirc on codebase there are some detection routines. I found a routine on codebase that is supposed to distinguish between the NMOS and HMOS variants of the PAL VIC: http://codebase64.org/doku.php?id=base:detect_vic_type interesting in its own if it works, but that's not what I need. > basically just count the cycles for a line (or a frame) using a CIA timer. Exactly what I meant with spending lots of time counting cycles ;-) -- SD! - http://e4aws.silverdr.com/ Message was sent through the cbm-hackers mailing listReceived on 2017-06-21 17:00:02
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