[TUHS] /dev/drum

[Charles Anthony]

On Mon, Apr 30, 2018 at 8:05 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu>
wrote:

>     > From: Johnny Billquist
>
>
>     > But how do you then view modern architectures which have different
> sized
>     > pages? Are they no longer pages then?
>
> Actually, there is precedent for that. The original Multics hardware, the
> GE-645, supported two page sizes. That was dropped in later machines (the
> Honeywell 6000's) since it was decided that the extra complexity wasn't
> worth
> it.
>
>
7 page sizes. AL39, page 40:

 PTWAM.ADDR
The 18 high-order bits of the 24-bit absolute main memory address of
the page. The hardware ignores low-order bits of this page address
according to page size based on the following:

Page size in words    ADDR bits ignored
    64             none
   128              17
   256            16-17
   512            15-17
  1024            14-17
  2048            13-17
  4096            12-17


I am unsure of exactly which model supported this, but somewhere in the
evolution from 645 to DPS8-M.

-- Charles
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://minnie.tuhs.org/pipermail/tuhs/attachments/20180502/5578b62a/attachment.html>