[Coco] S-video Prospects...

John Kowalski sock at axess.com
Thu Jan 5 18:07:47 EST 2006


Hi Everybody,

Well, I went and ordered a sample of the AD724 chip and just finished wiring
the sucker up to the CoCo's RGB video.

And...  it works.

I haven't gone as far as comparing the output against my old RGB-to-SVideo
converter, but so far it looks pretty decent, although probably not quite as
pristine as from my old converter.
80 columns looks fine and is perfectly legible.  If anyone is interested, I
might try taking some more photos of the video output to give people an idea
of the quality.

The circuit consists of:
1 x AD724 chip
1 x 3.57945 Mhz clock crystal
1 x 7805 (5V) voltage regulator
4 x 0.1 uF capacitors
3 x 220 uF capacitors
1 x 10 uF capacitor
1 x 82 pF capacitor
6 x 82 Ohm resistors
3 x 68 Ohm resistors

+ wires and connectors and a 2"x2" perf board.  Yes, the AD724 is surface
mount - it takes a special kind of patience to wire one up to a perf board :)

So, it works.  The big question for someone why may be looking into building
these things is being able to find a supplier who will sell these chips in
quantities of less than 100.

                                         John Kowalski (Sock Master)
                                         http://www.axess.com/twilight/sock/




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