Virtual memory

[Brent Hilpert]

On 2010 Nov 5, at 4:39 PM, Chuck Guzis wrote:
> On 5 Nov 2010 at 17:12, Brent Hilpert wrote:
>> I'm not familiar with the B5000 implementation (did I miss it in the
>> thread already?), but I did try to avoid restricting the def to that
>> of paging.
>
> The B5000, circa 1961 was an amazing bit of equipment.  Read about it
> here, then compare with later systems.
>
> http://www.ajwm.net/amayer/papers/B5000.html
>
> Makes the PDP-11 seem like a pile of Tinker Toys in comparison.

Well, you have to love a machine with a "HEYU" instruction (get the 
attention of another processor).

I was aware of many aspects of the B5000 series, from AotHoC articles, 
but not with the VM implementation technique. The article mentions the 
use of a descriptors to indicate memory segment availability, but 
doesn't describe much of the VM beyond that. It doesn't make it clear 
when VM was actually implemented, I had always been led to believe the 
ATLAS was the first VM machine, in the early 60's.

--

Outside the B5000 topic, it is amusing to read the writer's advice in 
1982 of "Machines worth keeping an eye on are the iAPX-432 and the IBM 
System/38".