Path: utzoo!dciem!king
From: king@dciem.dciem.dnd.ca (Stephen King)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Homebrew Genlocks
Keywords: Genlocks
Message-ID: <2450@dciem.dciem.dnd.ca>
Date: 24 Aug 89 17:30:47 GMT
References: <1326@mcrware.UUCP> <11695@cit-vax.Caltech.Edu> <2190@netcom.UUCP>
Reply-To: king@dretor.dciem.dnd.ca (Stephen King)
Organization: D.C.I.E.M., Toronto, Canada
Lines: 20

In article <2190@netcom.UUCP> hue@netcom.UUCP (Jonathan Hue) writes:
>How about using a Motorola MC1378 (Color Television Composite Video Overlay
>Synchronizer)?  This alone won't do it, but it looks like you just need to
>generate a couple other timing signals to get this thing to work.  It's in the
>Motorola Linear and Interface Integrated Circuits data book.

One problem you may have with this is getting a 28MHz clock (8x SC) for the 
Amiga from the 38MHz (10x SC) output of the the MC1378. I designed & built a
system a few years ago (68000, 512k) which used the 1378 to overlay
bit-mapped graphics onto a video signal. My system used a 14MHz (4x SC)
clock which was derived from the 38MHz using a single PAL. This gave an
unsymmetrical clock signal; my system didn't mind, but I don't know if the
Amiga could handle it. Apart from this, there may be difficulty in
obtaining some of the circuit components (200nS delay line, chroma bandpass
transformer) - I got a local distributor to give me some 'samples'. There
is a Motorola application note which includes a PCB layout for the 1378.
Best of all, it works!! 2 chips + assorted passive components = genlock.
-- 
                       Se non e` vero, e` ben trovato 
     ...{utzoo|mnetor}!dciem!dretor!king        king@dretor.dciem.dnd.ca