After a significative break on the subject, I finally managed to have a "perfect" display to my VGA LCD screen using a GB8220 and a simple 74LS02. The secret is on R03 that needs to have it's 4 high bit at least =2 (vSync width) ... but not zero. Knowing that, my setting for R00 to R09 on the 8032 at 50Kz/15.63Khz (measured at osciliscope) for text mode are (in decimal) : 63,40,53,33,33,7,25,32,0,8. Regards - Hervé Tous vos emails en 1 clic avec l'application SFR Mail sur iPhone et Android - En savoir plus. ======================================== Message du : 19/12/2013 17:53 De : "Rob Clarke " <firstname.lastname@example.org> A : email@example.com Copie à : Sujet : Re: PET video to VGA Here's my spreadsheet with all the timings from all common ROM's I could find plus the others that are on zimmers. You can use this to twiddle with the values and see the effect on the frequencies. http://inchocks.co.uk/commodore/PET/PET_CRTC.xls Anders is correct for the 80 column edit roms. For the 40 column ROM's the registers are at E7B1 and E7C3. Rob On 19/12/2013 13:21, Anders Carlsson wrote: > Hervé wrote: > >> - What are registers values supposed to be OK ? > > Perhaps André:s site can help you? > http://www.6502.org/users/andre/hwinfo/crtc/ > http://www.6502.org/users/andre/petindex/crtc.html > > It seems to that changing the register R2 would move the image to > either left or right. The second page has actual register values, see > the ones for CS/A65 as those were tuned for a 50 Hz TV. André also has > links to the composite video adapters and mentions that the CRTC > values need to be changed in order to get them to work. > >> - Locations, in this hacked ROM, to patch to change those registers >> values ? > > A quick hunt with the xpet monitor suggests $E72A (lower case?) and > $E73C (upper case/graphics?), but I'm not entirely sure. > > Best regards > > Anders Carlsson > > > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2014-04-03 00:00:03
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