[comp.sys.amiga.misc] I need to ground the PALs on my ancient A1000. How do I do this??!

chymes@valais.csmil.umich.edu (Charles Hymes) (03/15/91)

Help!
I need to know how to ground the PALs on my *OLD* Amiga 1000. Can
someone tell me how to do this or tell me where to get information on
how to do this?
I've been told that there is some document somewhere.
Thanks!
Charlweed Hymerfan

rich@documail.UUCP (Rich McCallister) (03/20/91)

In article <1991Mar15.150731.7009@engin.umich.edu>, chymes@valais.csmil.umich.edu (Charles Hymes) writes:
> I need to know how to ground the PALs on my *OLD* Amiga 1000. Can
> someone tell me how to do this or tell me where to get information on
> how to do this?

According to Amazing Computing article by Perry Kivolowitz of ASDG
(March 1988), you should connect 
   pin 10 of PAL "U6J" to pin 10 of PAL "U6K"
   pin 10 of PAL "U6L" to pin 10 of PAL "U6N"
Others have recommended tying all of these together, and connecting 
them to a ground on the motherboard "at a point just to the left of the
power supply connector (There is a row of 8 capacitors with ground on the
side nearer the connector)."
   I recently grounded the PALs on an A1000, trying to fix a noise problem
with an extra Serial/Parallel port board. I ended up connecting the grounds
of all 4 PALs together, and connecting them to a motherboard ground. That
didn't fix my problem, so I provided an extra ground from the Serial/
Parallel board to the PAL-and-motherboard ground. That worked.