More Commodore PET drives - more help?

From: Gordon JC Pearce <gordon_at_gjcp.net>
Date: Sat Sep 25 12:26:49 2004

Dave Dunfield wrote:

> Replaced ANOTHER 4116 DRAM in a CBM 2001-N last night - this makes 7 or 8 I've
> changed so far - symptoms are always the same - amount of memory "found" by BASIC

They were always a favourite for dead ZX Spectrums. I got good at
identifying the failing chip just by looking at the screen - there would
often as not be a one-pixel "pinstripe" across the screen. The "2" in
the copyright message was good, if the machine managed to get as far as
displaying it.

Since the chips ran *slightly* warm normally, and either ran very hot or
completely cold when they failed, I could identify them by feel - hold
the back of my hand above the memory to make sure one isn't clearly red
hot, then feel each one in turn until I found the knackered one. Wasn't
often wrong, either. Dead good, that. The things that impress you when
you're a spotty teenage computer geek.

Gordon.
Received on Sat Sep 25 2004 - 12:26:49 BST