Re: Zip Information

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

In article <3vu512$d5i@news-2.csn.net>,
Jawaid Bazyar <bazyar@hypermall.com> wrote:
> Does anyone know the function of the jumpers J3 and J4 on the Zip GSX
> board?

No, but from a quick check of the board with a continuity tester, I
can identify where they go.

J3 is a bit hard to identify.  The upper pin goes to the RESET pin of
the 65816, and to a feed-through under the ASIC.  The lower pin goes
to the bottom pin of T1 (which has no component installed) and to
another pin on the ASIC.  The top pin of T1 goes the Apple II's +5V
rail (or possibly the beefed-up processor rail, which is connected
through to +5V on my old card).

J4 has a default track connected between pins 1 and 2.  Pin 2 goes to
the ASIC.  Pin 1 goes to the IRQ signal on the 65816 and on the CPU
plug.  Pin 3 goes to the NMI signal on the 65816 and on the CPU plug.
The jumper appears to be for selecting between one of these
interrupts, but I don't know what the ASIC would need this for.

> J1 and J5 are processor connectors, J's 6-8 are for the
> Split cache modification, but I know nothing about the function of J3
> and J4. Furthermore, where is J2?

The slot connector.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand