Re: It works! IIgs RGB on PS-one LCD

[Mitchell Spector <mitch2gs@hotmail.com>]

David Murray <spamsucks@stopspam.com> wrote:

>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:

    You can find many examples of people hooking these up to other systems,
but you're the first person (that I know of) that's connected an Apple IIgs. 
In fact, your discovery made the news page over at www.a2central.com !
(see March 21st news blurbs).

>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.

    What's the response time like on this LCD? Do you see ghosting or
blurring when scrolling windows or the mouse pointer? Since it was 
designed for high frame-rate game console you'd think not, but then
the screen technology itself is about 3-5 years old.

>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... 

    According to one site, it's resolution is 640x480 (the maximum of the
Playstation 1). http://www.bit-tech.net/article/136/

    That looks to be so, since you'll see they have it working with a PC
VGA card outputting at 640x480. The IIgs Finder works in 640x200
resolution, which is somewhat of an odd resolution. Perhaps it's 
doubling the vertical lines to fit in 400 or 480 lines? (I'd need a more
detailed screen shot to see what it's doing). Most games work in 
320x200, how do those look? 

>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.

    Absolutely, since the Amiga and IIgs RGB displays work at 15.75 kHz.
I've successfully used my AppleColor RGB with my SuperNintendo, looks
incredible for color and sharpness.

    Back on the PSOne LCD. Does it support standard composite input?
I was thinking how it might make an excellent display for an Apple IIc/IIc+.
My old C-Vue LCD display has an extremely low contrast (much worse
than even a 1989 vintage Gameboy) and requires a strong overhead 
light source. It's also 1-bit black and white and vertically squashed.

    I wonder, if you go into the IIgs 'Display' text Control Panel and set it
for 80 columns, how legible is the text? I'm sure it at least could do 40
columns text and Low, High and Double-High resolution in color more
than acceptably. All you'd need is a standard RCA cable. 

Mitchell Spector