Re: help, RGB

[nathan@visi.com (Nathan Mates)]

In article <Pine.SUN.3.91.960916191758.10195B-100000@lo-pan>,
Cyrus Roton  <croton@ridgecrest.ca.us> wrote:
>There used to be a device, called "Mappler", which converted Apple analog 
>RGB (15-pin) to IBM digital RGB (9-pin). There seems to be plenty of 
>cards to output Apple RGB and plenty of IBM type monitors at low prices. 
>But how to interface the two???  Does anyone have info on this subject?

   An Apple II is not a Macintosh, especially when it comes to RGB
video out. Sure, the connectors are the same size, and both say
they're for Apple analog RGB monitors. But, the GS and most Apple II
RGB cards put out a horizontal sync signal of 15Khz. Pretty much all
modern Mac and PC RGB monitors require at least a 30Khz horizontal
sync signal.

   Also, I think that only the CGA/EGA monitors on PCs had 9-pin
digital connectors. SVGA is definitely 15-pin analog. (But, that's a
different 15-pin setup: 3 rows of pins vs 2 for Apples)

   Thus, a straightforward Mac RGB -> [S]VGA converter won't work
when connected to an Apple II. And if you want to be asking about a
converter hanging off a Macintosh, you should ask on a Macintosh
newsgroup.

Nathan Mates

--
<*> Nathan Mates http://www.visi.com/~nathan/      <*>
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