[rescue] Wanted: 8-bit ISA CGA or EGA card

[Steve Hatle]

Just a follow-up on this. I sourced a known good (and identical) CGA
card, and
the machine behaves exactly the same way, even with all other
cards out of the
system. 

Time, I guess, to start swapping around rows of RAM on the
motherboard
and see if I can isolate a fault there, but the machine does pass
the
RAM countup, and the jailbar/checkerboard display appears before that
happens. 

I guess if they always worked, it wouldn't be as much fun :-)
Happy New Year all,

Steve


-------- Original Message --------
Subject:
[rescue] Wanted: 8-bit ISA CGA or EGA card
From: "Steve Hatle" 
Date: Tue,
December 16, 2014 9:17 am
To: rescue at sunhelp.org

All,

I got a freebie IBM XT
(5160) that appears to have a bad CGA card in it.


...

Symptoms on the "bad"
card are that at power-on it puts up a "jail-bar"
like pattern with some
reverse flashing characters in it, and then will
start to display the memory
count and banner, but these are offset -
best way to describe it is like the
left "edge" of the screen is in the
middle of the physical display. So - the
banner text starts in the
middle
of the screen, and then wraps around to the
left.