Re: When 2114s fail

My experience with 2114 failures has generally been data lines stuck low,
and in the case of my Return Of the Jedi, I observed garbled sprites.

Fortunately for Defender, your RAM is socketed. You can move the RAM around
to see if the symptoms change without buying any parts. Certainly, a good
step would be to scope the address and data lines pre and post bus
drivers/buffers to look for any stuck signals. If you do find a stuck line,
at least you know you are in the right area.

You'd think our community would have coded a ROM with a set of test vectors
to put each of our motherboards through a series of tests... Maybe some
folks have done exactly this for some of the more common games? Basically,
if we wrote a Power On Self Test for a given microprocessor and tweaked it
for a given memory map, it would go a long way towards testing out the basic
health of our machines. My understanding is that the CAT boxes would offer
similar services, but in the absence of a CAT box, a test ROM would go a
long way.

Joel-

----- Original Message -----
From: "Neil Bradley" <nb@synthcom.com>
To: <rasterlist@synthcom.com>; <vectorlist@synthcom.com>
Sent: Saturday, April 12, 2003 1:40 PM
Subject: VECTOR: When 2114s fail

> Sorry for the double posts to both lists, but I thought it might be
> relevant to both types of games (and in my case I'm troubleshooting a
> raster and a vector game).
>
> When 2114s fail, what types of failures commonly occur? Do they stick
> address lines? Data bus lines? Just flat out won't store information? My
> immediate problem is with a Defender and I can't quite tell if it's an
> address decoder problem or a RAM chip problem, and am trying to find a
> rational way to troubleshoot it.
>
> If you have any experience with the 2114s and can post the types of
> failures you've seen, that'd be great. Thanks!
>
> -->Neil
>
> --------------------------------------------------------------------------
-----
> Neil Bradley In the land of the blind, the one eyed man is not
> Synthcom Systems, Inc. king - he's a prisoner.
> ICQ #29402898
>
>
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Received on Sat Apr 12 18:43:02 2003