[comp.sys.atari.st] Monitor connection?

jrd@STONY-BROOK.SCRC.SYMBOLICS.COM (John R. Dunning) (10/06/87)

Please forgive what may be a dumb (or already answered many times)
question; I don't normally watch this list.

I've got a 520 ST on loan, without a monitor.  I'd like to plug it up to
a monitor that I have lying around, but the pinout for the video from
the ST appears to separate all of R, G, B, HS, and VS.  My monitor uses
RG/SB, ie sync on green.  My question is, what does it take to mix the
syncs into green, the way my monitor wants it?  Can I just wire-or them
(I doubt it)?  Is there a standard piece of hardware I can use?  Can
someone tell me the schematic of a device to whack together?  I'm happy
to hack hardware, but am not usually a video hacker, so I'm not sure
what the right thing to do is.  

Any and all info appreciated.  Thanks in advance.