27 Jul
2003
27 Jul
'03
3:42 a.m.
-----Original Message-----
From: cctech-admin(a)classiccmp.org [mailto:cctech-admin@classiccmp.org]On
Behalf Of B.Degnan
Sent: 24 July 2003 21:18
To: cctalk(a)classiccmp.org
Subject: Pet 2001, (6550 unobtainium!) ??
Hello - I read your text from...
http://www.classiccmp.org/pipermail/cctalk/2003-January/014761.html
I have a similar problem, the screen is full of characters, and I
am trying
to figure out what is the cause so that I can attempt to fix. I am going
to try the 2114s from bgmicro.com as you mentioned. Any advice?
With my machines (except the TRS80 model 1 I've got) I've found that garbage
on the screen is nearly always bad video RAM, so yes replacing those 2 chips
is a good place to start. As you can see in the pix below my PET 2001 is
happy now.
http://www.binarydinosaurs.co.uk/Museum/Commodore/pet2001/pet2001.php
Of course your mileage may vary - there are other reasons for garbage but
they depend on whether the garbage is random or identical at every powerup.
If the garbage is identical you could have a bad RAM chip.
cheers
--
adrian/witchy
www.binarydinosaurs.co.uk - the online computer museum (New version!)
www.snakebiteandblack.co.uk - monthly gothic shenanigans