C= PC1 graphics problem

From: Michael Huth (520052975648-0001_at_t-online.de)
Date: 2003-02-10 23:08:25


I got a C= PC1 lately from a friend. It has a Motorola 6845 as CRT 
Controller. This controller
seems to be capable of a 80x25 Textmode and CGA Graphics. The Board has a 
RGB Connector and a Composite-Video Connector and 4 DIP switches. The DIPs 
seem to have an influence on the Video Signal.
The Problem is, I have only a TV or a BT878 based PC-TV card for Video 
Input. I tried the Video Out with the TV and couldn't get a Sync. Also my 
C128-RGB to Composite-Video Cable didn't worked.
With one DIP combination I could get a barely visible Screen with my PC-TV 
Card. The PC1 itself seems to be ok (until it waits for a boot disk).

So do I really need some CGA Monitor or is there any way to get it working 
with a usual TV (like the C128 RGB to Composite Video Cable). And what for 
is the Video-Out, if it does not works with a TV ?

I am not that hardware freak. I am lucky that I got it working again with 
some AT-Power Supply after the built-in broke down :-/.

Maybe these things help:
-There is a 15Mhz Quarz which seems to be for the DOT-Clock.
-The Video Out Signal seems to be generated with the help of some Resistor 
Array (not the sync though).


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