PDP-11/23 deskside machine

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Fri Mar 24 08:06:03 2000

> Virtual memory - yes! It grabs RAM if you have enough (which you do not)
> and the VM.SYS device driver makes VM: look like a disk drive. If you had
> 4 MBytes of memory and used 2 MBytes for VM:, that would give you a device
> of 4096 blocks.

VM: is not virtual memory, it is ramdisk. VM would be paging unused or
old sections of code to disk to make the system ram look logiccally larger
than the physical. RT-11 doesn't, it does swap jobs to a disk (or VM:).

True virtual memory on PDP11 is implmented in unix and RSX OSs.

Allison
Received on Fri Mar 24 2000 - 08:06:03 GMT