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[www].se [ftp].se [mirror].us [mirror].de
PowerFPU.hqx (145.87 KB)
MD5: 7d1011090af53daff293d7807ab2a199
For System 7.0 - 7.6 - Mac OS 9
[www].se [ftp].se [mirror].us [mirror].de
powerfpu13install.sit (272.02 KB)
MD5: fdd325296b5628e78a79a30d309cd3ee
For System 7.0 - 7.6 - Mac OS 9
This app works with: SheepShaver,

PowerFPU is a software 68K FPU emulator for PPC Macs. It's a Control Panel, similar to SoftwareFPU, but much faster and more efficient. This software may be necessary to run (certain) older 68K apps on PPC hardware.

PowerFPU is a high-performance 68K FPU emulator for the Power Macintosh from John Neil & Associates.

By working closely with the built-in Apple 68K emulator and redirecting 68K FPU calls to the high-speed PowerPC CPU, PowerFPU provides extremely fast 68K FPU emulation. PowerFPU is over ten times faster than SoftwareFPU, John Neil & Associates' other freeware FPU emulator, and faster than some versions of the Motorola FPU chip itself! The chart below shows where PowerFPU performance falls in the range of Macintosh FPU performance:

Time to execute John Neil & Associates FPU Time Test FPU benchmark:

PowerFPU 1.0 (emulation) 1.60 (Power Mac 8100/80)
16MHz 68882 FPU (chip) 1.65 (SE/30)
16MHz 68881 FPU (chip) 2.53 (Mac II)
SoftwareFPU 3.02 (emulation) 20.6 (Power Mac 8100/80)

With PowerFPU you can run all 68K FPU applications at full-speed on your Power Macintosh!

Excerpt: — John Neil & Associates   

View the author Tom Pittman's page:

See Also: SoftwareFPU

Architecture: PPC

Requires a PPC Mac.
"One unlucky user discovered that opening the PowerFPU control panel disables it, requiring a re-install. Just install it and don't open it, if you have that problem."


lilliputian's picture
by lilliputian - 2019, December 13 - 3:49am

@MikeTomTom: That makes sense! Thank you!

@Jatoba: I thought maybe, but just wanted to make sure!

Jatoba's picture
by Jatoba - 2019, December 13 - 3:27am

@lilliputian Sorry, that was a reply to @sfp1954, it's just that while I was writing my reply, his message got edited out, so it looks strange now.

MikeTomTom's picture
by MikeTomTom - 2019, December 13 - 3:22am

So FPU calls from emulated 68k software being run on PPC machines would be calculated in-software instead of being sent to the in-built FPU?

Correct. The 68k emulator in a classic PPC Mac does not (and cannot) emulate 68k floating point calculation, so the brilliant PowerFPU steps in here. 68k software needing an FPU does not see, recognize, nor can utilize a PPC built-in FPU in PPC Macs.

lilliputian's picture
by lilliputian - 2019, December 13 - 3:19am

Oh, I know that PPCs have an FPU, but it sounds like any FPU related calls coming from 68k software are not processed by it (unless, of course, you are using this Control Panel).

Jatoba's picture
by Jatoba - 2019, December 13 - 2:03am

A PPC chip without FPU? I'm extremely confident that never existed... But I can't say so for sure. As for L2 cache, I'm less certain, but I think there was always some of it, no? I haven't seen the processor documentation of super early PPC processors, but I'd be surprised if even the 1st gen PPC had zero or less than 128KB of L2 cache.

Now, L3 cache would be a very different story... I wish I could have one of those 7457 cards with 4MB of L3 cache cards (and overclocked). Sad

Edit: I looked it up, and while FPU/MMU was there ever since the PowerPC 601, I guess it is true the very first gen didn't have L2 cache. Shock That makes one appreciate all the following successors even more.

sfp1954's picture
by sfp1954 - 2019, December 13 - 1:45am


lilliputian's picture
by lilliputian - 2019, December 13 - 12:18am

That interesting! So FPU calls from emulated 68k software being run on PPC machines would be calculated in-software instead of being sent to the in-built FPU?

Jatoba's picture
by Jatoba - 2019, December 12 - 11:09pm

Thanks for the info! That makes sense.

Franky233's picture
by Franky233 - 2019, December 12 - 7:52pm

All 3D rendering programs (including Ray-Tracing) or most of mathematical ones, for example... I remember my old LC 475 with a 68LC040 processor. But yes, this software is only for PowerPC machines. So, it has been created for acceleration of such programs...

Jatoba's picture
by Jatoba - 2019, December 11 - 2:13am

What 68k Mac programs depended on the presence of an FPU? It'd be helpful/interesting to have a list for that, since the vast majority of 68k software doesn't require one.

3371-Alpha's picture
by 3371-Alpha - 2016, September 13 - 6:55pm

You know I wonder if this is compatible with Speed Doubler's 68k emulator? I don't actually own a computer old enough to use this, but I am still curious.

MacinTricks's picture
by MacinTricks - 2011, May 10 - 6:57am

The additional download is the installer for PowerFPU 1.1 and the updater to version 1.3 (not 1.3b1). However, it is unclear which version 1.3 or 1.3b1 is more recent (a lot of programmers don't rigorously follow software release version conventions). Incidentally, the original BinHex (hqx) file does not have a valid time stamp from its creation. Doing a legit install seems to eliminate the pesky "Install from master disk" message.

As for the "disabling red X" issue, try shutting down and cold-starting the computer. The control panel will disable after a restart, so the computer must be shut down every time to use PowerFPU.

IIGS_User's picture
by IIGS_User - 2009, May 6 - 5:26pm

Thank you for uploading this part of software to match my request at the SoftwareFPU entry.