VAX-11/750 memory in 11/70 ?

Johnny Billquist bqt at
Tue Mar 10 18:06:07 CDT 2015

On 2015-03-11 00:03, Johnny Billquist wrote:
> On 2015-03-10 22:40, Pontus wrote:
>> Hi all
>> I was told that VAX-11/750 memory could also be used in an PDP-11/70 (or
>> maybe some other model). Is this true?
> Yes. :-)
>> I have also read that there are three kinds of memory boards for the
>> 11/750:
>> M8728: 256k byte memory array;
>> M8750: 1M byte memory array;
>> M7199: 4M byte memory array.
>> (As well as some third party boards.
>> Which one of these, if any, could be used in an 11/70?
> Only the 256K ones.

By the way, while I'm at it.
The 4M ones can only be used if you have the right memory controller in 
a 11/750 as well, and then only two of them, in the first two slots. The 
rest are at most 1M cards, if I remember right.

And if you absolutely want to use 1M cards in an 11/70, ping me, and 
I'll walk you through the howto. (Update have done this in the past. It 
is not trivial, but it is possible.)


Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

More information about the cctalk mailing list