Speed Control Extension?

[Jorpho]

I remember way back in the day playing some games that crawled on a Mac Classic that ran much too quickly on an LC 475. At some point I can dimly recall reading about an extension that could be used to slow a 68k Macintosh down, but I can't seem to find it anywhere. Is my memory playing tricks on me?

I did find something called PowerForce at http://www.cornstalker.com/freeware/archive.php , but I don't think that's the same thing. (Lots of cool stuff there.)

[24bit]

I tried many cpu throttling solutions some time ago in emulation.
The names are escaping me right now.
None of them worked. Many crashed the emulator.
Still it would be a nice addition to find a working solution.

[adespoton]

Yes; I remember the one you are referring to, but can't bring up the name at the moment. I do recall trying it years ago in vMac (pre Min) and having it crash on startup. Considering not even MACSBUG is functional under current emulation, you're not likely going to get these things to work well. I think most of them just used debugger calls to feed waits into the instruction queue.

If it doesn't work in vMac, it's unlikely to work in BII/SS. However, you could probably use something like screen refresh rate to limit speed to some degree.

[Adam P]

If it doesn't work in vMac, it's unlikely to work in BII/SS. However, you could probably use something like screen refresh rate to limit speed to some degree.

The refresh rate limit for B2/SS exists to speed up emulation, not slow it down, updating the screen less so drawing takes fewer CPU cycles.  B2/SS will always run as fast as they can, all cycle count considerations pretty much ignored.

I think most of them just used debugger calls to feed waits into the instruction queue.

Mini vMac is supposed to handle all of that; these extensions should work there.  I don’t see how they wouldn’t; there are no software means for lowering the CPU rate (except portables…).  Besides, Mini vMac is the emulator with a speed feature ('s' in Control menu, with 'z' being the slowest setting), meaning you probably wouldn’t need to use speed limit extensions anyway.

Update: PowerForce is for G3/G4 Macs.  SheepShaver emulates a G4, but without an MMU, and without a full CPU either.  There are a multitude of CPU settings with the real thing, including settings for the caches; SS doesn’t really handle anything there beyond making JIT work.