Re: Ramworks III problem

[Mike Maginnis <maginnis@computist-project.net>]

On 22 Aug 2006 16:16:52 -0700, a2aviator@gmail.com wrote:

>The answer is probably in the thread- but the thread isn't all showing
>for me right now...
>
>If the card is producing garbage on insertion and activation, it's
>either got bad logic in the simple circuit portion or it's got bad RAM
>in bank A. Within the first two ICs. The rest of it is non-existant
>until called apon.  The four ICs in the middle are probably labeled
>"AE1", "AE2", etc.

Four ICs in the middle (between the expansion headers, closest to the
keyboard end of the card)  have nothing on them - closer examination
reveals that whatever was printed on them has been scraped off.

The other four are: 74LS245N, 74LS08P, 74LS374P and 74F32N.

>
>Somewhere I have some notes as to what those really are. They're just
>relabled 74xx series. Nothing on the card is special except the
>GAL/PAL.
>
>If simply swapping some RAM from elsewhere on the card into the A bank,
>or even within the A bank produces the same results then I'd be going
>to look at the simple circuit part of the card which is the 244/245/373
>stuff along with the A bank of RAM. It's repairable. No question there.
>The PAL is not even needed for basic operation. It's a pretty
>straightforward card.
>

Switching the DRAMs in the A bank didn't.  This is sounding more and
more like a solder job, which is out of my skill set.

>Some out there in the wild even have normally labeled ICs on those
>positions, so if everyone looks at their RAMWorks cards and notes what
>ICs are installed in the center area between the two expansion headers
>and make a note of what is in what position. They are labeled Ux,
>(example, U2, U3, U4)

Mike Maginnis
maginnis@computist-project.net

The Computist Project
http://computist-project.net