new Applicard

[alex.freed.007@gmail.com]

Still mixed results with the Applicard clone. Last time I had
a fake Apple and a fake z80, all built on an FPGA. The result:
simple test communicating with the "card" worked, but CP/M
wouldn't boot.

To limit the number of unknowns I found an old board with a z80
and sockets for static memory. A little surgery plus a couple
extra chips made it pretend to be an Applicard (I hope).

http://mirrow.com/FPGApple/PCPI/board1.jpg

A recycled and re-programmed PseudoDisk prototype acts as an
Apple bus interface.

http://mirrow.com/FPGApple/PCPI/interface.jpg

A logic analyzer shows that it is executing the code in the
boot ROM more or less as it should. I couldn't make sense of
some of the boot code. If left alone for over 2 minutes it
does start some diagnostics routine, but the last code written
to the Apple interface is $42 and it doesn't change any more.
This is likely an indication of some fault, but I don't know
how to interpret it. The OEM manual doesn't cover it.

To make the long story short, this prototype plugged into a real
Apple 2e acts much like my FPGA model: a lot of code is written
to the z80's memory and it loops in $F8Bx region waiting for
data from Apple. At the same time Apple loops around $B0Cx polling
for data from the z80. Needles to say neither CPU is getting anywhere
fast. Oh, and nothing got printed on the screen either.

Questions to everybody and Steven Hirsch in particular:

1. Any idea what the diagnostic code stuck at $42 means?
2. Any software test I could run?
3. Please try the image http://mirrow.com/FPGApple/PCPI/pcpiboot.dsk

Does it work with a genuine Applicard? I don't have one unfortunately.

-Alex.