Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ucbvax.BERKELEY.EDU
Path: utzoo!watmath!clyde!burl!ulysses!ucbvax!info-atari
From: info-atari@ucbvax.UUCP
Newsgroups: net.micro.atari
Subject: Re: 520ST video outputs
Message-ID: <8601162010.AA07460@mitre-bedford.ARPA>
Date: Thu, 16-Jan-86 15:10:53 EST
Article-I.D.: mitre-be.8601162010.AA07460
Posted: Thu Jan 16 15:10:53 1986
Date-Received: Sat, 18-Jan-86 00:46:11 EST
References: <350@ihnet.UUCP>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The MITRE Corp., Bedford, MA
Lines: 16

Presumably the "analog RGB" output is synced at 60 Hz, else very few RGB
monitors would work right on it.  Or is there a way to select (there must be)
a 60-Hz output?  If so, then it wouldn't be too hard to whip up a composite
video signal from the RGB, or even a 60-Hz monochrome one.  On the other hand,
a 60-Hz composite signal must exist at the video modulator input, so it could
also be sneaked off from there.  Then at most a low-pass filter would be
needed to feed a 60-Hz monochrome monitor, and in fact the composite signal
could probably be used, as it was designed to be more or less compatible.

Does anybody know whether the whole thing shifts gears to 60 Hz when you plug
into the RF modulator jack?  Or can you simultaneously run RF at 60 Hz and
monochrome at 70 Hz?  This may be the key to why you can't run both monochrome
and color monitors at the same time -- if in fact you can't.

						-John Sangster
						jhs at mitre-bedford.arpa