Talk:VAX/Archives/2014

Latest comment: 9 years ago by Guy Harris in topic PRIME Computer reference

PRIME Computer reference

From the article:

'"VAX" is originally an acronym for virtual address extension, both because the VAX was seen as a 32-bit extension of the older 16-bit PDP-11 and because it was (after Prime Computer) an early adopter of virtual memory to manage this larger address space.'

Why do we call out Prime here? There's nothing special about Prime. Lots of computers had virtual memory, and using it to manage an increase of address space is nothing new. The PDP-6/10 family went from 18 to 22 bit physical addresses and 23 bit virtual addresses as well and used several different forms of virtual memory to manage it. All existed before Prime. IBM had similar developments before Prime.

The reference to Prime should be removed. — Preceding unsigned comment added by 168.159.213.206 (talk) 19:02, 11 August 2014 (UTC)

My guess is that they were talking specifically about machines considered "minicomputers" or "superminicomputers"; there were definitely machines and OSes that did paged or segmented virtual memory before the VAX, such as the GE 645 under Multics, the IBM System/360 Model 67 under TSS/360/CP/CMS/etc., the Burroughs B5000 under MCP, etc.
But Prime wasn't the first minicomputer company to offer virtual memory; apparently Norsk Data's Nord-1 had it in 1969. Guy Harris (talk) 20:52, 11 August 2014 (UTC)
I vaguely remember that PRIME was considered special because it had the first 32-bit minicomputer. John Sauter (talk) 21:11, 11 August 2014 (UTC)
The Nord-5 article claims, albeit without a reference, that it "is believed to be the first 32-bit minicomputer". Guy Harris (talk) 21:27, 11 August 2014 (UTC)