On Wed, Jul 16, 2014 at 4:12 PM, David Riley <fraveydank at gmail.com> wrote:
- VAXBI (super-proprietary with little known
documentation)
I think Al just posted something a couple days ago, and I may have
some design docs in the basement from when Software Results got a
VAXBI license (we made a prototype run of boards - they worked but the
market had moved on so we never sold out of that first run). I did
the firmware for that product and its driver for VMS from the ground
up. It was super-proprietary (and rigidly licensed). You essentially
had to work from DEC's PCB template files (they supported multiple
design packages IIRC) and add your circuit to the "BI Corner" which
they maintained with an iron fist. There's a double-row of VIAs, and
you just ran your signals to the right place and the bus area was
taken care of for you. There are no "unauthorized" peripherals for
the BI that I'm aware of. You *had* to buy BIICs (BI Interface Chips)
from DEC. We got one or two when we got our license,
then for the
prototype run, I was able to pick up used 2MB boards from the reseller
market for about $50 and pull the BIICs (they were socketed) instead
of buying new $350 chips. Between that and "refurbed" (used) RAM and
CPUs, I got the manufacturing price down $500 per board from the
initial numbers.
I have a couple VAXBI COMBOARDs in my 8300 in the basement (along with
a few of those 2MB (T1008) boards). Generically, they are built
around a 68010 CPU with a 16-bit-32-bit discrete bus adapter
(reading/writing 1/4 of the '010 address space triggers a bus read or
write including upper/lower word latching) with 2MB of local RAM, a
Z8530 serial rigged for sync operation (pins 15 and 17 for external
data clock) and 64KB of local ROM. The driver works with the firmware
to upload a payload application into RAM, but if one could fit all the
code into the ROMs, that functionality could be deprecated.
- SBI (is that even separate from VAXBI?)
SBI is 11/78x and entirely separate.
-ethan