Message-ID: <202@sdcc12.UUCP>
Date: Wed, 6-Mar-85 18:48:29 EST
Article-I.D.: sdcc12.202
Posted: Wed Mar  6 18:48:29 1985
Date-Received: Sun, 10-Mar-85 05:07:35 EST
Organization: U.C. San Diego, Academic Computer Center
Lines: 27


	I want to run the composite output of my IBM color graphics
card directly into a Sony Betamax video tape recorder. It seems that
all I'll need is an RF converter whose output I'll run into the
antenna/cable input of the VCR. It seems too simple to really work
and so, before plopping down my money for an RF converter, Id like 
to see if anybody has any knowledge, opinions, or experience
reguarding such a hookup. iSpecifically:
 
	-Do you think this scheme will work ?

	-If so, do you recommend any particular RF converter
	 or source for them.?

	-What about the Video inputs onthe recorder? could they
	 be used in some manner that wouldn't require the RF
	 converter?

Please respond via Mail - I'll summarize if there's interest

Thanks in advance - Ken Cluff

-- 

						Ken Cluff

			ucbvax!sdcsvax!sdcc3!sdcc12!ph28kc

Message-ID: <153@rruxo.UUCP>
Date: Mon, 11-Mar-85 14:08:35 EST
Article-I.D.: rruxo.153
Posted: Mon Mar 11 14:08:35 1985
Date-Received: Tue, 12-Mar-85 09:11:37 EST
References: <202@sdcc12.UUCP>
Organization: Bell Communications Research, Piscataway N.J.
Lines: 16

I'm not shure what your budget looks like, but for about $2500 or so you
could have a device that I found very helpful. It will translate RGB analog,
RGB TTL, or video into a form that a specialized video monitor can use. Both
the translator (called a switcher, because it can take up to 10 inputs) and
the projector (about $20K) are distributed by a place called INFLIGHT SERVICES
Inc..  They are somewhere in Manhattan. We use it mainly for presentations
and training classes. It is actually readable at 132 chars! (many aren't at 
80). I forgot to mention - the switcher can output whatever it inputs. ie:
if you want video output - you got it. no matter what the input was.
good luck. 

Vince Hatem
Bell Communications Research
rruxo!vch

Article-I.D.: cadvax.140
Posted: Mon Mar 18 18:59:54 1985
Date-Received: Tue, 26-Mar-85 03:47:52 EST
References: <202@sdcc12.UUCP>
Organization: Megatest Corp., San Jose, CA
Lines: 34



Disclaimer: I have never tried to do the hookup you suggest, but can offer
some useful information.

For one, if you have a composite video input on you VCR, you don't need an RF
converter.  You can take the direct video from the system, to the VCR.  This
gives a better signal than using a $5 RF converter, as those things have real
"el cheapo" RF oscillators.  I know that on my VCR, there is a composite input
and output, for both video and audio.  There are two phono sockets at the
back, for audio and video output, and two on the front for input.  From what
I'm told, VCR's use a mechanical sync. (Yeugh!!!), whereby the rotating heads
are actually in sync. with the incoming signal.  TV stations keep their sync
signal *precise*, so once the VCR locks in, it will hold.  Unfortunately,
a lot of personal computers use el cheapo sync. circuitry as well, thus the
VCR *may* have trouble staying in sync with the computer.  This problem arises
with either a direct-connect, or an RF converter -- be warned.  It shows up
characteristically, as screen-roll (loss of vertical sync), or as a screen
with diagonal bars (I don't know what the tech term for this is, but it's
caused by loss of horizontal sync).  As a matter of interest (or trivia), most
video protection schemes involve a slight variation in the sync field, which
(supposedly) screws up the recording on a second VCR.  It can also show up
as "interference" on the playback VCR, hence the protection scheme is normally
injected at the beginning, during the credits.  Anyway, back to your question:
I would suggest a direct hookup, and watch out for bad sync.  If you do get a
poor picture from the VCR, I wouldn't dash out and buy an RF converter, as it
won't help your problem, you'll just have to wait until they start digitizing
VCR's.  I hope this is some help...
		- Der Tynan

PS: Excuse the posting, but I couldn't send mail...

          ***** All flames to /dev/null please! *****
        "May the blessings of Jeyes Fluid fall upon you"