David Empson wrote:
Linards Ticmanis <ticmanis@gmx.de> wrote:Michael J. Mahon wrote:The answer is in the schematic--the NTSC color signal is created not by the multiple-of-3.58MHz pulse scheme that is the Apple II standard, but by a chrominance modulator driven by the RGB signals. Therefore, its color rendition is not dependent on its pixel rate.Does this apply only to SHR modes, or also to IIe compatible modes?Probably all modes.
Agreed.
The IIgs RGB output emulates the colour behaviour of 8-bit Apple II video modes, e.g. alternating green/violet pixels in HGR mode, with an odd coloured pixel every 14th (yellow or brown). The NTSC composite output can generate a proper colour burst derived from the emulated colour, producing the right effect on NTSC, but with proper colour encoding rather than a simulated colour burst and having to rely on timing tricks.
Yes, that's my take on it, too. Just for fun, I think I'll take a look at the IIgs composite video with a scope... It always seemed to me that the SHR modes were "alien" to the Apple II, and now it appears that *all* IIgs composite video is different. -michael NadaNet networking for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."