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Re: IIGS mass storage ideas
Linards Ticmanis wrote:
Smohn Jith wrote:
So what is involved in getting a TV to display //gs and what would be
Especially a TV that already has a RGB input (read: all models with the
SCART (i.e. Euro-AV) connector) is quite easy to adapt:
http://www.ole-s.com/teknisk/SCART-apple.htm
American TVs usually aren't able to accept RGB from the outside world in
any standard way. You'd need to get the schematics and install extra
sockets that bypass the tuner and the Composite-to-RGB circuits.
This was the approach that I was thinking of.
Alternately you could probably build some resistor matrix that converts
RGB to YCbCr ("Component") if your TV has a component input. Beyond that
it gets more complicated. RGB-to-Composite or RGB-to-SVideo conversion
requires more complex circuits.
And conversion to composite or S-video both involve compromises in
bandwidth, particuarly of the chroma signal. Of course, composite
is already available, together with its severe bandwidth limitations.
involved in getting a VGA to do it?
This is far more complicated since the VGA monitor needs at least about
twice the line frequency of the IIgs or TV standards. You have to
basically store the picture that's coming from the IIgs into some kind
of RAM and then output it repeatedly to the monitor at a higher speed.
My approach would not synthesize a VGA signal, but would slow down the
horizontal sweep to 15kHz. I don't think this is a difficult problem
in practice, but the proliferation of monitor designs makes a general
modification unlikely. (It's hard to make a monitor go *faster* than
it's design maximum, but slower is easier--a couple of capacitors in
the right places might be enough if the sweep circuits are analog.)
-michael
Music synthesis for 8-bit Apple II's!
Home page: http://members.aol.com/MJMahon/
"The wastebasket is our most important design
tool--and it is seriously underused."