From: pepke@scri1.scri.fsu.edu (Eric Pepke)
Subject: Casio LCD TV's
Date: 11 Oct 91 18:02:36 GMT
Organization: Florida State University, but I don't speak for them



The Spine-Chilling Saga of the Casio LCD TV's, Part 1

I bought a couple of Casio LCD TV's, model TV-8500.  These are 8 cm by 5.5 cm
color jobbies, battery operated.  This is appreciably bigger than the Lynx
screen, and I had decided, from squinting at various televisions through
lenses, that this was about the minimum size that I want to use for homebrew
eyephones.  These were on sale, so I got them for less than $200 apiece.

The color, when driven by a video signal, is somewhat washed out but still
pretty good.  I think that one of the problems is that the internal lights are
too bright.  They'd certainly be too bright for the inside of a helmet, so it
will be neccessary to change the driver circuitry.

I got tired of waiting for enough spare time to rip one apart, so I did it
anyway.

Inside, it has two basic elements.  There's the display module, which contains
the display, the fluorescent tubes, and some custom chips.  It's sealed in a
can.  There's also the analog board, which has the buttons and jacks and the
audio circuitry.  I have only seen one side of the analog board, but it appears
to be all discrete.  Lots of tiny little surface-mount components.  The display
module and the analog board are connected with a 24-conductor ribbon connector
and six fatter wires for power and the two fluorescent tubes.  I am hoping that
it will be possible to figure out what's going on in that ribbon connector
and get into the circuitry there.  I know that there is a PAL as well as an
NTSC version.  I am hoping that they engineered it so that the analog board
does all the PAL/NTSC and RF, and that the display module is responsible for
all the actual picture generation.

Maybe I'll get lucky and find a chip on the reverse side of the analog board
and get enough information to conclude that the lines on the ribbon connector
include address lines!

More as I find it out.

Eric Pepke                                     INTERNET: pepke@gw.scri.fsu.edu
Supercomputer Computations Research Institute  MFENET:   pepke@fsu
Florida State University                       SPAN:     scri::pepke
Tallahassee, FL 32306-4052                     BITNET:   pepke@fsu

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