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Path: utzoo!mnetor!uunet!seismo!kitty!larry
From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: comp.graphics
Subject: Re: PC Controlled VCR
Message-ID: <1865@kitty.UUCP>
Date: Tue, 21-Jul-87 23:16:38 EDT
Article-I.D.: kitty.1865
Posted: Tue Jul 21 23:16:38 1987
Date-Received: Thu, 23-Jul-87 07:06:47 EDT
References: <1880@isis.UUCP>
Organization: Recognition Research Corp., Clarence, NY
Lines: 32
Summary: Easy enough to build yourself

In article <1880@isis.UUCP>, ross@isis.UUCP (Ross McConnell) writes:
> Does anyone know of a VCR that can be controlled via a serial
> or parallel port from a PC? I just want to give basic commands
> such as RECORD, STOP, REWIND, etc, under program control.

	I know of VCR's controlled by PC's for interactive education,
product ordering, etc. - such as the NCR INteracTV (tm) - but that
is probably not what you want (these systems are generally play-only).
	However, it would be fairly easy to build what you want.  Take
a VCR with a _wired_ remote - such as the Panasonic NV-8420.  The wired
remote consists merely of a keypad connected to a cable.  Use a reed
relay matrix to replace the keypad and provide isolation.  Connect an
octal latch to a parallel printer port, using the printer strobe line
to reload the latch.  Using suitable relay driver IC's, drive the
select relays from the octal latch.
	All you have to do is write bytes to the printer port to
control the VCR.  I have already done this to a Panasonic NV-8420,
and have the following commands available: STOP, PLAY, RECORD, FORWARD,
REVERSE, SEARCH FORWARD, SEARCH REVERSE, SLOW, PAUSE, and FRAME ADVANCE.
I actually used optoisolators instead of reed relays - but the reed
relays are a safer bet unless you feel totally comfortable working with
the VCR logic.
	You can build this entire circuit for less than $ 20.00 in
components.
	If you use the above suggestion, don't forget that you have to
write a null (00H) to the printer port after each command (except for
the SEARCH commands), since the remote keypad is momentary in nature.

<>  Larry Lippman @ Recognition Research Corp., Clarence, New York
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