22 Apr
2024
22 Apr
'24
1:45 p.m.
On Apr 22, 2024, at 4:24 PM, Mike Katz via cctalk
<cctalk(a)classiccmp.org> wrote:
Well, the SB-1 is a multi-core pipelined machine with multiple caches and all sorts of
other complications. And the company certainly had a cycle accurate simulator. They were
reluctant to let it out to customers, but we leaned hard enough. It was slow, indeed.
Certainly not a cycle per minute; I'm pretty sure it was a whole lot more than a cycle
per second. Given that the code I was debugging was only a few hundred instructions long,
it was quite acceptable.
Speaking of slow emulation: a CDC 6600 gate level model, in VHDL, is indeed slow. Now
we're indeed talking about a cycle per second. I'm thinking I could translate the
VHDL to C and have it go faster (by omitting irrelevant detail that VHDL carees about but
the simulation doesn't).
paul
Again, not impossible, but very likely not
feasable.
Well not possible with the hardware available at the time.
If one cycle per minute or less is acceptable then I guess it was possible.
That is why we used in circuit emulators to do cycle accurate counting on more complex
machines. This machines were clunky and unreliable but they worked for the most part.