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From: wtm@uhura.neoucom.EDU (Bill Mayhew)
Newsgroups: rec.video,sci.electronics
Subject: Re: RGBS -> Y/C
Summary: historical note for completeness
Message-ID: <1991Jun06.030022.28683@uhura.neoucom.EDU>
Date: 6 Jun 91 03:00:22 GMT
References: <13965@pasteur.Berkeley.EDU> <1862@vidiot.UUCP>
Organization: Northeastern Ohio Universities College of Medicine
Lines: 42

Just a minor note.  The Mindset computer made a brief appearance on
the market in approximately 1983.  The Mindset was largely an IBM
XT clone, but had an NTSC compatible video output and offered
genlocking and video attachments similar to the Amiga that followed
several years later.  Unfortunately, the backers of the Mindset
undercapitalized the project and there were some bad management
decisions.  The Mindset had the right idea and was one of the first
multimedia machines to market.

Also the DEC Rainbow's RBG output was RS-170 compartible, with
negative sync on green.  The Rainbow advanced video graphics board
used a NEC 7220 graphics engine, which was pretty hot stuff in
1983.  Of course, the Rainbow was another marketing disaster,
though, DEC sold a lot of Rainbows by standards of lesser
companies.  With a ReGIS interpreter, the Rainbow could do some
neat things.  DEC's graphics terminals were also pretty easy to
cobble into composite video, the VT-240 in particular.  By modern
standards, the video resolution was not great.  Looks like Ken
Olsen finally has accepted that PCs aren't a passing fad with the
Tandy and Apple associations.

Sony also began selling an XT clone computer that could genlock to
3/4 umatic decks in 1983.  I recall seeing a demonstration system
using the machine to simulate level III interactive video discs
using two VTRs.  It was agonizingly slow.  We still have one of
those Sony beasts hooked up to an industrial Sony LD palyer in our
media center.

IBM CGA was a pain in the neck because IBM chose to use positive
sync for some strange reason.  The common wisdom was that IBM used
the inverted sync to slow down sales of competing RGB monitors that
were already on the market that would have to be reworked to
support IBM sync.  This would guarantee a protected market for
IBM's own equipment.

Bill

-- 
Bill Mayhew      NEOUCOM Computer Services Department
Rootstown, OH  44272-9995  USA    phone: 216-325-2511
wtm@uhura.neoucom.edu   ....!uunet!aablue!neoucom!wtm
via internet: (140.220.001.001)