From: Marko Mäkelä (marko.makela_at_hut.fi)
Date: 2003-02-14 18:14:07
On Fri, Feb 14, 2003 at 04:34:09PM -0000, Christopher Phillips wrote: > How common is the IIe? I'm not familiar with the revision nomenclature. As common as the Commodore 128, 128D, 128DCR and 128CR. VIC-I is the common name of the audio/video chip in the VIC-20, VC-20 and VIC-1001. The video chip in Commodore 64, UltiMax, SX-64, 64c and 64G are called VIC-II. Of each chip, there exist at least two different versions (PAL and NTSC) and usually several revisions. > this reminds me of the TEST bit on the vicIIe. You can detect a vicIIe by > reading the raster, setting the test bit for a few cycles, and checking the > raster again. Anyone unfamiliar with this may want to check the 60hz trick > regarding this bit. It seems while the test bit is set, the vicIIe advances > one raster per 1mhz cycle(!). ;) Yes, that was why I said why I wouldn't use the test bit. If you dig up older discussions on this list, you might see a reference to a program that displays an interlaced on the C128 by abusing the test bit to generate odd and even frames. A similar effect could be achieved on the plus/4 by writing the horizontal raster register if I remember correctly (Levente, are you listening? :-)), but it might not work on some TVs. While we are at this, has anyone been able to produce a proper Ceefax (teletext, Bildschirmtext, text-TV) signal with a Commodore computer? None of the TVs or monitors I have access to is equipped with a Ceefax decoder, so I have an excuse for not having tried it. :-) Marko Message was sent through the cbm-hackers mailing list
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