Kmc11-a

[Doug G]

I just found a M8204 unibus board that I've had stashed in a box for 25 years or so. For the life of me I can't remember what we may have used this for. Being unibus, I assume we used it or tested it with the 11/34 systems we built.

Does anyone know what was a KMC11 could be used for? We weren't programmers, so it would have been some off-the-shelf use.

 

[RSX11M+]

It's a specialized Processor module envisioned by DEC to provide customers with a programmable I/O subsystem to offload the main CPU. It can access UNIBUS devices and memory. It contains on board memory as well which could be configured based on the need. Can be employed with a DMC11 (M8201 or M8202) Remote Line Unit for EIA, DDS, and up to 1M bps Modem.

Here's a user manual and a Programming Manual on Bitsavers.

Some uses seem to include a PLC, although I would think the most common one would be in a PDP-11 IOP for PDP-10s.

Any of that ring a bell?

It's not a common module in my experience.

 

[Doug G]

Some uses seem to include a PLC, although I would think the most common one would be in a PDP-11 IOP for PDP-10s

Nope, we had nothing to do with PDP-10's.

Where these modules ever used with peripherals like particularly serial muxes? Our systems used to have at a minimum of a couple 8-line muxes, and some had as many as 96 serial lines.

I'm going to look through other old stuff from those days and see if I can come up with any clues why we had this thing. And thanks for the links!

 

[RSX11M+]

I saw a thread post about it being used with an 8 or 16 port DZ11, but the details were very sketchy. This application was not familiar to me.

 

[vaxorcist]

Hi,

My 1981 DEC "terminals and communications handbook" tells on page 148 about a "COMM IOP-DZ" made from a KMC11 and up to six 8-line DZ11s.

The COMM IOP-DZ was used to offload the main processor from handling a great number of serial lines.
It transformed the simple character interrupt DZ11 device into a high performance dma device.

Want a scan of the four pages?

I'm currently in the process of aquiring a DMC11 that uses a similar communication processor to drive a synchronous serial line.
The DMC11 has its microcode in ROM instead of in RAM as with the KMC11.
I want to use the DMC11 for networking old VAXen with ancient pre-Ethernet VMS versions using DDCMP-DECnet.

The DMC11 will soon be available as a new simh device for simh PDP-11s and VAXen.

Regards

Ulli