🚀 go-pugleaf

In article <89216.120136BHB3@PSUVM> BHB3@PSUVM.BITNET writes:
>Does anybody know hwat the loewst cost device that would generate a 60Hz
>video sync signal would be.
...
>The specific application is an Ardent Workstation computer.
>The RS-170(NTSC) output from it requires that you put in a external
     ????????????
>sync signal.

RS-170 and NTSC are very different color signals, RS-170 uses separate
R G and B lines and NTSC puts it all on the same signal.
In 3 wire RS-170 setups, the sync signals (negative pulses) are often
sent along the same line as the green video signal (positive waveform)
during retrace.  A fairly simple comparator circuit set to trigger on the
Vsync level should work as a Vertical Sync Separator.  It is best to look
up some kind of RS-170 spec (preferably from Ardent in your case) to get
the exact specs on the signal.

 ^   ^  Forrest Cook - Beware of programmers who carry screwdrivers - LB
/|\ /|\ cook@stout.ucar.edu (The preceeding was all my OPINION)
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