Re: ZipGS and PC Transporter

[dempson@actrix.gen.nz (David Empson)]

In article <CuuIp5.7x2@freenet.carleton.ca>,
Michel Bois <ad657@FreeNet.Carleton.CA> wrote:
> 
>  Help!
>  
> I seem to be having problems with my PC Transporter and
> Zip GS 10MHz/64K cache. For a while I had my PC Transporter taken out.
> During that time I purchased my Zip GS. I finally had the time
> to properly reinstall the PC Transporter. After the initial ram check
> after running the transporter, the screen would seem to go black with
> some grey bars across my screen like it lost horizontal lock.
> The only thing came to mind was that this problem didn't occur before
> installing my ZipGS. So I removed the ZipGS and tried the PC Transporter
> again and no problems this time.

It is a hardware problem.  I had the same problem when I first got my
ZIP GS.

According to ZIP, it is a problem with the PC Transporter loading down
some of the bus signals too much (a clock signal, if I remember right).
They are able to fix the problem by modifying the ZIP.  I believe the
mod involves a capacitor and a few other simple components, but I
don't know the exact details.

I don't understand how this would affect the PCT's video output, and
why it doesn't affect anything else.  The PCT works fine apart from
the video.

Whatever the problem was, ZIP were able to fix it when I sent my card
back to them to have it modified.

It is only a problem with older PC Transporters.  A friend of mine had
a reasonably new PCT, and had no trouble when he installed his ZIP.

The newer PCT uses 256k x 4 DIL DRAM chips instead of 64k x 4 ZIL
DRAMs.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand