24 Oct
2005
24 Oct
'05
12:45 p.m.
On Monday 24 October 2005 12:00, a.carlini at ntlworld.com wrote:
Huw Davies wrote:
Purdue is correct, 11/784 isn't. The 11/784 is the quad-CPU version of
the 11/782. Purdue's dual-VAX didn't have a DEC model number, because
they never (officially) sold it.
Sharing the SBI made a much more usable dual-processor machine, where
both CPUs could access I/O and *all* of the available memory, not just
4MB of it.
Pat
--
Purdue University Research Computing --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
Certainly the only 11/782 I know of (Melbourne
University) was
split to get much better performance. Basically all I/O (and hence
all of VMS) had to occur in the "master" 11/780 so all that could
be run in the slave was CPU intensive jobs. As soon as your CPU
bound process wanted to do something other than compute it had to
be scheduled in the "master".
The 782 certainly was two 780s joined at the hip. I thought that the
SBI was joined up too but that might be the Purdue (?) VAX-11/784.