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

[Bob Koehler]

In article <5586381E.9040801 at spam.com>, Don North <idontwant at spam.com> writes:
> 
> The PDP-11/20, PDP-11/05 (aka PDP-11/10), and PDP-11/04 were MMU-less UNIBUS 
> machines so they only supported a maximum of 56KB of memory. The UNIBUSes on 
> these machines were 18bit address to be compatible with the UNIBUS, but of the 
> full 256KB UNIBUS address space the low 56KB of memory could be addressed, and 
> the upper 8KB of address space was the I/O page.

   I think you missed the 11/34.  IIRC no MMU, only UNIBUS mapping
   registers.  I/O space was 18 bit, but RAM was 16.