[Info-vax] OpenVMS I64 V8.1 "Evaluation Release"?

[Bob Koehler]

In article <jkqlkp$6aa$1 at speranza.aioe.org>, glen herrmannsfeldt <gah at ugcs.caltech.edu> writes:
> 
> As someone else noted, VAX doesn't allow for all 32 bits in the
> physical address, even at the architectural level. 

   The very first VAX, the 11/780, had a 30 bit SBI.  With only 30 bits
   on the bus, and memories starting at 1M, it made a lot of sense to
   use a 30 bit hardware architecure.  For decades VAXen ran on 30 bit
   and narrower busses.  But later on there was an ECO to the architecture 
   to take advantage of a wider bus and IIRC, you could actually order
   a VAX with 4GB RAM.  Of course, no one process could actually use all 
   4GB since system space never used up the full upper half.

   And I for one, would not like it if P1 got too close to P0.  I've
   never run out of stack space on a VMS system and I don't want to
   learn what the error message is.