[Info-vax] OT: IA-128 ???

[Bart.Zorn@gmail.com]

On Oct 19, 3:19 pm, koeh... at eisner.nospam.encompasserve.org (Bob
Koehler) wrote:
> In article <paul.nospam-D6099A.13245618102... at pbook.sture.ch>, "P. Sture" <paul.nos... at sture.ch> writes:
>
>
>
> > RSX-11 could address more than 16 bits to support extra RAM, but I
> > forget the details.
>
>    Under RSX-11M, when we moved from a 512MB 11/34 to a larger 11/44,

A PDP 11/34, at least those without third-party add-ons, supported a
maximum of 256 KB memory. The 11/44 supported up to 4 MB.

>    we moved from disk resident to memory resident overlays.  You
>    still had to work out the overlay, but the overlay manager just
>    updated the MMU registers, it didn't have to fetch stuff from
>    the disk.
>
>    This, of course, leads to different behaviour for memory resident
>    variables.
>
>    I don't recall separate I and D space support under 11M, but that
>    might be because we didn't use it.  Or maybe you needed 11M+ to
>    get that.

AFAIK, only RSX-11M+ and RSTS/E supported separate I and D space.

Bart