Amiga and Atari fans used to lord over their Apple-eating brethren the fact that Cupertino never moved to the most advanced 68k processors — so for a while, thanks to 68060 accelerator cards, the fastest thing running Macintosh software was an Amiga (or Atari). After all these years, the Macintosh community is finally getting the last laugh, as [zigzagjoe] demonstrates an actual Macintosh booting with a 68060 CPU for the first time in a thread on 68KMLA. Video or it didn’t happen? Check it out below.
The Mac in question is a Quadra 650, which is a good choice since it was about the last thing Apple sold before switching to PowerPC, and ran the 68040 processor. [Reinauer] had already produced a 68040-to-68060 socket adapter (the two chips not being pinout compatible), so the hardware part of the battle was already set. Software, however? That was a different story, and where [zigzagjoe] put in the effort.
We’re spoiled by decades of backwards compatibility in the x86 instruction set; Motorola wasn’t as kind back in the day, and the 68060 isn’t fully compatible with the earlier 68040’s instruction set. They did provide a translation that [zigzagjoe] was able to build into his custom ROM, though, which is how he’s able to get the Mac to boot and install System 7.1, the newest version that would boot.
Alas, the full 66 MHz clock speed [zigzagjoe] proved unstable. To make branch prediction work, he had to clock down to 50 MHz. Considering the ‘040 clocked at 25 MHz in the Quadra 650, that’s still a considerable improvement in clock speed.
At 66 MHz and giving up branch prediction, DOOM runs at 16.4 FPS. It slowed down (14.3 FPS) at 50 MHz, and branch prediction. We expected branching to have a greater impact, but apparently not. While DOOM is perhaps not the best benchmark on this hardware, it does answer the most important question you can ask of any bit of kit: yes, it does run DOOM!
While Apple has long since abandoned the 68k in favour of PPC, x86, and finally their own implementation of ARM, there are always enterprising upgraders.
Now if someone could just get a NeXT computer to boot with one.
That would require significantly more effort that just a socket adapter, since NeXT uses the multiplexed bus mode of the 68040 which the 68060 does not support.
See also https://www.nextcomputers.org/forums/index.php?topic=3855.0 for details.
Bummer.
What about Quadra 840av? It was the fastest ‘040 Macintosh Apple made at 40MHz and could probably do 66MHz or faster ‘060.
Cool! This is impressive! 😃
The 68060 deserves more love, I think. It’s the Pentium of 68k series.
Even it’s run in 68040 compatibility mode, it has certain advantages.
Btw, in the early days of 68k Macs the Macintosh had a dumb framebuffer.
That’s why Atari ST and Amiga with their Blitters could draw GUI-ish things using less overhead.
Later 68k Macs optionally could use dedicated graphics cards with some intelligence, too.
Similar to those Windows/GDI accelerators in some Windows 3.1 PCs.
Apollo Computers who make Vampire Amiga have a 68080; that is the fastest 68k cpu I have seen. I liked the 68k family, too bad they didn’t continue them instead of PowerPC. Ya, the blitter was ahead of its time mid 80s early 90s, but then it became slower than CPUs or newer graphics cards.
Yes came here to say this!!! Amiga’s and ST`s are still the fastest 680×0 mac!!
And PCs are still the fastest Amigas?! 😉
“The result is an Amiga emulator capable of running 68k applications between 5 – 10 times faster than a 68060 system.
According to SysInfo (an Amiga benchmark utility), a 1 GHz AMD Athlon emulates an Amiga equivalent to a 450 MHz 68040.”
http://www.bambi-amiga.co.uk/amigahistory/emulators/amigaosxl.html
Just checked! That 68080 is interesting! It’s an FPGA, it seems.
So it’s not exactly same thing as using an Motorola 68060 as in the article..
Still impressive, though! Considering that PowerPC platform on Mac side
merely emulates an 680EC40 without FPU (there are software 68k FPU emulators such as Software FPU or PowerFPU).
It makes someone wonder how the Mac platform would have
been doing in the 90s if the older 68k models had increased overal
market share of the Mac platform by having such upgrades installed.
Not as rival for the PowerPC models, but to uphold the existing installation base of Macs.
As for the Amiga.. I never really understood the use of PowerPC accelerators, it seemed wrong to me.
Now I do kind of understand the idea because of how the Mac platform did the switch.
But I’m not sure if it made sense same way for the Amiga software which is/was more low-level most of the time.
I also don’t like that newer CPU accelerators apparently didn’t work
on the real Amiga OS anymore, which was Kick 1.3/Workbench 1.3 from the 80s (to me).
You know, the one with the Orange/Blue/White color scheme.
Never understood the purpose of AmigaOS 2 and up.
Except for preparing HD0: for installation via Kickstart 2 (has internal HDD routines) once and then go back to using Kickstart 1.3.. ;)
The branch predictors in those days were’t the greatest, and these CPUs aren’t very speculative (if at all) so there’s much they can do with predictions other than prevent a few stages of pipeline flush.
not much*
Replacing DRAM by SRAM (Static RAM) would be one workaround to get better memory performance, maybe.
Unfortunate that the video starts with a cat obscuring the power-on (briefly) and that annoying background music covering up the startup chime.
C’mon people, take some pride in your work when making demo videos.
Hi! Come on, the cat is the star of the video! 🙂 Every cat is, in fact! 🩶
About the video.. I don’t like that its vertical. But maybe that’s because of Youtube shorts.
Here’s another interesting video, horizontal: https://www.youtube.com/watch?v=lk_ZgpcZBEY
Much better!
16 fps on doom is i486 territory and not even a fast one.
Pentium, which is the equivalent of ‘060 provides ~50fps at 66MHz while i486 is good for 21 fps at same clock.
Perhaps doom is not showing 68k cpus in the best light.
Doom on the Mac was a 3rd party port.
As a benchmark its terrible.
Marathon would provide a better benchmark between anything 68020 up to this 68060.
When the 6.8MHz 68k Mac SE came out, the Apple LaserWriter was a 12MHz 68k. If you didn’t mind programming in FORTH, your printer was the fastest computer in the room…
There are many recently developed 68060 boards (for different Amiga models), that clock at up to 100 MHz and could be faster 68k-Macs with Shapeshifter.
Only problem: 68060 (at least with full MMU and FPU) is getting rare and you don’t want to burn it too soon by overclocking.