>Holm Tiffe wrote:
Jerome H. Fine wrote:
Holm Tiffe wrote:
Ben Sinclair wrote:
I was just looking up VAXstations the other day on eBay. I checked
again now for 4000's, and the prices seem crazy. Is there something
particularly special about them, or is it just the usual eBay
craziness?
..that are the smallest and fastest VAXen so it is not so unlikely
that the prices are crazy...
Why you don't use an simulator (E11, simh) for the job?
That sounds like a good idea to use SimH for the VAXstation. However,
I suspect that E11 (Ersatz-11) would be a bit difficult to use to emulate a
VAXstation since E11 is exclusively for the PDP-11.
As for the individual who mentioned the speed of an emulator, I have used
both SimH and Ersatz-11 on a 750 MHz Pentium III. SimH probably runs
at about the speed of a PDP-11/93, probably even faster. However, Ersatz-11
runs 15 times as fast for CPU speed and about 100 times as fast for hard
disk I/O.
On a 2.83 GHz Q9550, Ersatz-11 ran about 100 times the speed of a PDP-11/93
for the CPU and hard disk I/O was probably about 200 times as fast. As just
one example, on a real DEC PDP-11/93 with ESDI hard drives, it took about
4 minutes to copy about 32 MB from one physical hard drive to a different
physical hard drive. On the Q9550, it took less than 1 second. I was using
RT-11 in all cases. I would assume that an I7 CPU would be somewhat faster,
but maybe someone else has some benchmarks.
Yes. Jerome he is right, he ist not intrrested in your great numbers since
hi want to emulate not a PDP11, but a VAX.
But I suspect that there might be a few individuals who are also
interested in
emulating the PDP-11, so those "great numbers" might be helpful to them.
The other point to emphasize is that SimH does a great job of emulation,
but is not the fastest application. If someone was interested in producing
code which executes in the manner in which Ersatz-11 does it for the
PDP-11, but doing so for a VAX emulation, the results might be spectacular.
Jerome Fine
