Paia 8700 Computer/Controller
First
Posted Nov 12, 2004
Updated 4-25-2025
This page is intended to help people who might be trying to get their
old Paia 8700 working. The schematic, as originally published,
seemed to lack certain details, so I have redrawn this using Orcad and
layed out a new PC board using Protel. I don't intend on making
any of these boards. However, I will post both the Protel file
and also the CAM files so you can if you wish get the boards made
yourself. They should be mechanically the same as the
original. It is posible there might be a few circuit differences,
but they should be functionally the same.
Schematic of Original Paia 8700
Well, here it is 21 years later. I am trying to make a "new"
8700 computer/controller. I have modified or changed a lot about
the 8700. It is really only an 8700 in spirit. It is not
going to be really compatable with the original at all. First
off, I am using a W65C816 rather than a 6503 ( or for that matter, a
6502). It is going to have a 8 digit alpha-numberic display,
It is going to only have RAM. Non volatile memories
(EPROM/EEPROM//etc)are not at all easy to find these days. It
will have a MIDI port, a pair of 6522 VIA chips, a slightly more
advanced synthsizer interface (you know, QUASH, etc), an interface for
a FATAR keyboard.
You will find a link below to the scematic as it stands today (4-25-2025).
One of the things it will also have, if I can get all of the parts onto
the board, is a logic analyzer that will record all of the bus activity
for debugging. It will capture about 32000 clock cycles with of
data.
And since there i 4-25-2025 (pdf)
Original Manual
.