Emulators

[Joerg B. Micheel]

On Fri, Jan 21, 2000 at 01:16:40PM +1100, Warren Toomey wrote:
> In article by emanuel stiebler:
> > Hi,
> > Anybody here, who made some benchmarks of the different simulators (supnik,
> > apout, ...)
> > 
> > What I'm looking for is something like:
> > supnik version xxx on pentium 2 350 MHz using linux, is xxx times faster
> > than a 11/73.

Us too! :-)

The problem is that it doesn't scale that simple. Each and every
instruction has the parsing overhead. Next comes execution overhead.
You'll find that the parsing is pretty constant, no matter whether
it is a NOP or some sophisticated MUL command. The execution speed
varies heavily, very often it is alot faster than the original
hardware. IO has seen a tremendous speedup, we can benefit here
from todays hardware alot. Just remeber how long it took to get
a prompt or echo when hitting the keyboard. As a result, the
original feeling of the real machine is lost, very unfortunate.

As a rough summary, simple commands do not improve (much), whereas
everything complex speeds up with the emulator. Harti has done quite
a bit of testing on different instructions and compared them to an
LSI11/73 (KDJ11A). The emulator was run on a i486 at the time. Have
a look at the p11 distribution, it should be in Tests somewhere.

Regards,
	Joerg
-- 
Joerg B. Micheel			Email: <joerg at begemot.org>
Begemot Computer Associates		Phone: +64 7 8562148
40 Masters Avenue, Hillcrest		Fax:   +64 7 8562148
Hamilton, New Zealand			Pager: +64 868 38222

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