It works! IIgs RGB on PS-one LCD

[David Murray <spamsucks@stopspam.com>]

Okay.. maybe I'm the first..I can't find anybody else who has done it.  I 
connected the IIgs RGB display to the RGB inputs on a Playstation PS-One 
5" LCD screen.  it is acutally amazingly simple and requires no logic 
circuits, or resisters, caps, or anything.  Here is a picture of it 
working:

http://galaxy22.dyndns.org/iigs_psone_1024.JPG

Of course, the picture isn't the highest of quality, the image on the LCD 
actually looks quite a bit better in real life.  

There are some pros and cons to this setup, though.

First off, you actually get proper colors on your display without the 
color-fringing effect like you get on composite.  The same as having an 
Apple RGB monitor connected.

Cons are resolution.  I am not 100% sure how many pixels are on this 
screen, however, I'm guessing 352x240.  That isn't a wild guess.. It is 
an educated guess based on some experiments I did with my Commodore 64 
hooked up in composite mode.  So in the IIgs high-res mode, you loose 
some pixels horizontally.  However, it is still readable, in fact MORE 
readable than using the composite output in high-res mode... 

This brings up some interesting things.  THis means an Amiga and Atari ST 
can use this same hack.  That also means you could hook a playstation 
into an Amiga or Apple IIgs monitor in RGB mode and get a super crisp 
picture.   Might be another worthwhile hack.

I will eventually post an exact pinout of what I did.. but if anybody is 
interested in trying this at home I can give you a few pointers.  In 
order to get the display to come on it needs to sense +5V on Pin-10 and I 
ran a wire from the 7805 voltage regulator on the inside of the screen to  
pin-10 on the connector.  Seemed to work.  Also the LCD only has one 
video ground so you have to tie the Red, Green, and Blue grounds together 
from the IIgs.  Otherwise everything is pin for pin.  I used a piece of 
solid-wire CAT5 cable just to solder to the screen and then to poke in 
the holes of the RGB connector.  Now that I know it works, I'll build a 
DB15 cable and do all the wires up nice.