#PDP INTERNAL MODEMS
4 messages in this thread
HELLO
We are in the process of building a BBS using one of several PDP's
(an 11/23 (MINC) , an 11/34a, and a 11/44) and we found a board in the
34 marked MODEM V.35. Of course, we have no documentation on it and
wondered if anyone new if it could be a 9600 baud or not (the board
number
is M8203 & M8207). Also, if anyone knows where we could find a reference
telling what card number is what, we would appreciate it. We know we
have several pieces of process control hardware that we wouldn't be
using, but we don't know what is what. Thanks again.
The M8203/8207 is a DMP11, which is a high-speed inter-processor
communications link (synchronous). It was a relatively obscure device and
I can't put my finger on any specs right at the moment, but I'd bet it runs
much faster than 9600bps, probably 56Kbps, perhaps even 1-1.5Mbps.
Note that V.35 has NOTHING to do with V.32, which is the 9600bps modem
standard.
-Bill
As Bill replied, the boards constitute a DMP-11 communications interface.
The DMP-11 implements DECs DDCMP point to point method of allowing 2 or
more computers to talk amongst themselves. It is capable of 56kb to 500kb
in full duplex mode or 1mb in half duplex. One DMP11 can control as manay
as 32 'slave' ports in a multi-party network.
Anyway, no modem is on board – the label you mentioned must refer
to something else.
I think the "modem" designation actually refers to the "line driver"
portion of the DMP-11… the part that talks to the cable between the
machines.
-Bill