MEM11 Status Update

Ethan Dicks ethan.dicks at
Tue Sep 1 10:01:29 CDT 2015

On Sun, Aug 30, 2015 at 1:08 AM, Guy Sotomayor <ggs at> wrote:
> The MEM11 is a multi-function memory board for Unibus based PDP-11
> computers.  It contains:
>  * 128KW memory
>  * Emulates console ROM & boot ROMs
>  * 2 SLUs (DL11s)
>  * KW11K
>  * KW11P
>  * KW11L
>  * KW11W
>  * RF11 (emulating up to 8 RS11 disks)
>  * KE11

Nice collection of features!

> The main objective is to provide the memory and I/O necessary
> to be able to run Unix V1

I am very interested in the MEM11 for this exact reason.  I have a
PDP-11/20 that I'd love to do this with.

According to
Unix v1 requires/supports:

"32K, RF-11 + RK03 disks, KE11A module [extended arithmetic element
for multiply/divide], DC-11 8 TTYs, TC-11 DECTape"

I haven't dug through the device driver code, but I expect that the RK
driver would support either the RK11-C (Flip Chips) or the RK11-D
(M7254, M7255, M7256 and M7257) since AFAIK they are
register-compatible.  I have both, but the RK11-D has been tested/used
(the RK11-C has a lot of parts and a lot of connections to corrode).

At least an RK11-D and one or more RK05s is a lot easier to find than,
say, an RF11.


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