[Info-vax] OT: obscure PDP11 OSes (even more dinosaury)

[Bob Koehler]

In article <714921e2-99c8-459e-aa32-d86830f4335c at googlegroups.com>, John Reagan <xyzzy1959 at gmail.com> writes:
> On Friday, June 26, 2015 at 10:05:53 AM UTC-4, Bob Koehler wrote:
> 
>> 
>>    I think you missed the 11/34.  IIRC no MMU, only UNIBUS mapping
>>    registers.  I/O space was 18 bit, but RAM was 16.
> 
> True.  However, I saw WAY more 11/34A systems which did have an MMU.  Was the 11/34 upgradable to the 11/34A or was it a system swap?

   IIRC, the only difference between an 11/34 and an 11/34A was a cache.
   We had an 11/34 we were doing processing on, and an 11/34A serving as
   the DECnet front end to a DECSYSTEM 2050.  We eventually upgraded the
   11/34 to an 11/44.  The we replaced the disk resident overlays with
   memory resident overlays.