From: sakelley@euclid.ucsd.edu (Scott Kelley)
Newsgroups: rec.video,rec.video.production,comp.sys.mac.hardware,comp.multimedia
Subject: Need to Build Cable Between Video Deck and Macintosh
Date: 27 Sep 92 22:49:34 GMT
Followup-To: comp.sys.mac.hardware

Sorry for the excessive cross-posting, but I'm not sure who exactly to
ask about this sort of thing...

I'm getting ready to drag my mac over to a television studio so we can
try to grab some QuickTime clips from their professional video gear.
(For those who don't know, QuickTime is a sort of digital-video
multimedia extension for the Macintosh). I'm working on trying to figure
out and build cables appropriate for the control ports on some of their
video decks so that we can have the computer do asynchronous frame
grabbing automatically (i.e. the computer tells the deck what frame to
display, then grabs that frame, then tells the deck to advance to the
next frame, etc.) with the computer controlling the video deck through
the serial port.

I already have a specification for a cable that should go between the
mac and a Betacam, 3/4" U-matic, or 8mm deck. It specifies a 9-pin D
connection on the video deck end. So that cable's no problem.

However, the other deck I want to go to is a Sony D-2 digital video
deck. It apparently has a 15-pin D-connector that provides an RS-422
interface to the deck. And it's this deck that's got me stumped. Can
anyone tell me how to make a cable for it? The main difficulty I'm
having is that I'm used to RS-232, and both the mac and this deck
actually want to talk RS-422. And I don't know how to work with RS-422.
What gets connected to what? Can anybody help me build a cable for this?
Here's what I know about the pinouts of the two devices:

Sony Deck (DB-15):    Apple Serial Port (DIN-8):
------------------    --------------------------
2  Rx-                  1  HSKo
3  Tx-                  2  HSKi
8  Spare                3  TxD-
9  Gnd                  4  Gnd
10 Rx+                  5  RxD-
11 Tx+                  6  TxD+
12 +12v                 7  NC
13 Frame Gnd            8  RxD+
14 Gnd
All others NC

For RS-422, Do I connect Tx+ to Tx+, Rx+, or Rx-, or what? I've got no
idea. And I don't want to damage their mind-bogglingly expensive video
equipment!!!

This whole project is basically a big experiment to see how the quality
of broadcast video compares to the S-VHS that we've tried so far. I
don't know a thing about production video equipment, and the people with
the video stuff don't know anything about QuickTime. We're hoping to
teach each other. But if anyone has any suggestions about what to
try/look for/watch out for, I'd be interested to know. But most of all
I'm desparate to get a cable built! If you can tell me how please email
me ASAP! Thanks!

Oh, btw, the Mac end is a IIci with a RasterOps 24STV video capture
board. I don't know what model(s) of video decks we're going to
experiment with; probably a variety.

Thanks for any help! Post or email, I'll summarize if there's interest.

Scott

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Scott Kelley, sakelley@ucsd.edu, (619) 534-8560
Multimedia Interactive Learning Laboratory (MILL)
Department of Biology, UC San Diego
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