7 Oct
2020
7 Oct
'20
11:29 a.m.
On Wed, Oct 7, 2020 at 11:04 AM Paul Koning <paulkoning at comcast.net> wrote:
Well it does appear that M8704 DMS11-DA "can't do anything on its own"
directly through the UNIBUS. From a quick visual inspection it only
has power and grant continuity traces on the card edge connectors. The
connection to the controlling KMC-11 is through the 40-pin Berg
connector. So without a KMC-11 an alternate interface through the
40-pin Berg connector would be needed.
On Oct 7, 2020, at 12:06 PM, Glen Slick via
cctalk <cctalk at classiccmp.org> wrote:
...
I was curious about this DEC M8704 DMS11-DA that sold cheap a few days
ago. It has eight SMC COM5025 "Multi-Protocol Universal Synchronous
Receiver/Transmitter USYNR/T" chips:
https://www.ebay.com/itm/373243388363
Apparently it can't do anything on its own. It needs to be connected
to a UNIBUS through a companion KMC11 processor board, which might not
be too common if someone wanted to put together a working
configuration.
That model number isn't familiar.
A KMC-11 is simply a microprocessor that sits on the Unibus and does Unibus cycles to
another device on behalf of the host. The idea is to offload operations so the host can
ask for block transfers and the KMC does the individual character I/O operations needed.
That said, it clearly is not correct that "it can't do anything on its
own". The KMC-11 reaches into the device via its Unibus CSRs. If you can find a
description of its operation, or reverse engineer it, you can clearly write a device
driver for it that doesn't rely on a KMC-11.
paul