Re: Cheese Video Box

[mjmahon@aol.com (Michael J. Mahon)]

Ed asked:

>Hello all:
>I just acquired one of these nifty little buggers from the internet.  It 
>is a scan doubler that has an S-Video and a composite input and will 
>output that information to a VGA/S-VGA monitor.
>
>What I was wondering is if anyone has hacked one of these to take the 
>RGB output of the IIgs?  I looked up the specs on the chips inside 
>(Averlogic's AL250 and Phillips SAA7111) but just can't figure out where 
>I'd patch in an RGB signal for the doubler to work on.  If you 
>understand this stuff and can lend me a hand, I'd certainly appreciate 
>it.  (It is for my portable IIgs project.)
>
>http://www.averlogic.com/video_converter/AL250.html
>http://www-us.semiconductors.philips.com/acrobat/datasheets/SAA7111_3.pdf
>
>Granted I could run the composite video out from the IIgs, but I was 
>hoping for a better picture than that.

Yes, you will be disappointed in the resolution if you input composite
or S-video.

The problem of getting RGB into the chip is that it must be digital.
It requires the upper five bits of Red and Blue, and the upper six
bits of Green.  Of course these must be clocked into the chip at
the correct rate.

It would be a simple product, but a non-trivial hack, to make this
modification, IMO.

-michael

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