Squeezing more memory into a process on a pdp 11/73

[paul]

> I am running a Unix system on a pdp 11/73.
> As you may or may not know this machine/OS combination
> assigns 64k to programme and 64k to data for any single process.
> I am doing a fair amountof image processing work and would dearly
> love to know a way to squeeze more memory into a single process
> (I have 1.5M all together).
> Surely someone has faced this problem before ... did you solve it ? How ?

If you run VenturCom's VENIX on an 11/73, you can take advantage
of our Shared Memory segments, which allow a process to create
a large memory buffer, and window a segment of the data space
through the buffer.  Manipulation of the data segment requires
the use of a special system call.  Once the window is positioned
at the desired location, access of the memory is direct:
the windowed portion of segment is right in the program's data space.
Incidentally, you can also use the VENIX code-mapping facility to
(transparently) have a program code space larger than 64kb.


-------------
Paul Kleppner
VenturCom, Inc.
617/661-1230
{seismo!harvard,genrad!mit-eddie}!cybvax0!vcvax1!paul