Path: utzoo!attcan!uunet!wuarchive!brutus.cs.uiuc.edu!apple!bloom-beacon!mit-eddie!mit-amt!adam
From: adam@mit-amt.MEDIA.MIT.EDU (Adam Glass)
Newsgroups: comp.sys.mac
Subject: Re: MicroTV and NTSC
Message-ID: <580@mit-amt.MEDIA.MIT.EDU>
Date: 24 Aug 89 15:05:28 GMT
References: <4086@shlump.nac.dec.com> <4360@ogccse.ogc.edu>
Organization: MIT Media Lab, Cambridge, MA
Lines: 44

afoster@ogccse.ogc.edu (Allan Foster) writes:
> adam@mit-amt.MEDIA.MIT.EDU (Adam Glass) writes:
>>software that slows the scan rate of the card down to NTSC scan speed slows
>>the computer down 40 ro 60%. You're going to have one _SLOW_ machine, if
>>it works at all.
>
> No Not at all.

You're wrong. It was stated earlier that MicroTV will slow the computer down
up to 30%. And Apple specified that your computer will be slowed down by the
RS-170 hack (I'm not certain of the percentages, but 40-60% sounds familiar).

> Sure you caould have the set up described.  With a splitter out on the
> video cable so that it hooked up to both the MicroTV and a monitor
> you could indeed se what you were doing in a window.  Make for some
> interesting recursive stuff tooo...

No, you're wrong again. Hook a camera (only do this with chip cameras --
you'll burn tube cameras!) directly to a monitor such that you can see
realtime movement when you move the camera. Point the camera DIRECTLY at
the TV. What do you see? Depending upon how your equipment is setup/white
balanced/etc., you will see one solid color in the monitor (usually white)
-- feedback. Point the camera at the edges, and you can see neat "recursion".
The MicroTV/NTSC hacks will give you pure feedback white -- the output of
the video card will be directly channeled into the MicroTV, resulting in
uninteresting solid video feedback.

> ago and there was no apparent slowdown at all.  Why should there be?
>
> All the init does is change some of the hardware registers in the card
> changing what it displays, the mac should not change speed at all!

It's the flicker filter that makes the video stable. Apparently, it looks
jittery and unstable without the filter.

> PS. I would really like to see myself in a window!

Why?

Adam
--
"What?! He didn't fall? Inconceivable!"  (email: adam@media-lab.media.mit.edu)
"You keep using that word... I do not think it means what you think it means."
(All stolen quotes taken from The Princess Bride) Hmm... 18 spaces left. Moof!