• Hello, Guest! Welcome back, and be sure to check out this post for more info about the recent service interruption and migration.

68060 in Mac

dolek

New member
Hi, I'm Amiga user but recently I've bought Macintosh 475. According to threat on Mac68k forum I've tried my 060->040 adapter with full 68060 CPU from Amiga with this Mac. When I power on it I've got not "beep" sound as in normal operation but something like "melody". I think that's mean CPU is working fine but something is wrong with startup procedure in ROM, maybe problem with model recognize? Is there any way to run such setup? Maybe there is any ROM version which can handle this or maybe someone can make custom ROM which can cheat CPU recognizing procedure to force always seeing 680LC040 CPU?
I've post here because the forum linked above looks like "dead", I can't even create account on it.
Greetings,
Mark
PS. I think my post should be understandable but may have language mistakes, so sorry for that (I come from Poland).
 

cheesestraws

Well-known member
The bad news is: there is no way to run an 060 in a Mac and keep it as a Mac. Apple abandoned the 68k architecture entirely after the 040, and 060 support was never added to the ROMs. The melody is 'the CPU is running code but hits an error talking to hardware very early'.

Amiga adapters get around the incompatibilities between the 060 and 040 by means of a number of tricks, most of which are Amiga-specific. It won't work unless you're willing to do some serious ROM hacking that nobody else has got working, I'm afraid.
 

dolek

New member
Hi, thanks for the answer. 060->040 adapter is not an Amiga trick. It is official feature of 68060 CPU described in MC68060 user's manual. Something like 68040 fallback mode. Chapter called "Using an MC68060 in an Existing MC68040 System ". There is also info about "MC68060 to MC68040 PGA to PGA Bus Adapter" available on market. Amiga starts with it even if 68060 specific libraries are missing. In that case Amiga see 68060 CPU as 68LC040 (68040 without FPU). According to "sysspeed" test program 68060 without proper library loaded is about 33% slower (66MIPS to 44MIPS).
 

Daniël

Well-known member
Regardless, the 060 is missing instructions that the Macintosh requires, so it won't work without somehow editing the Macintosh ROM. The closest anyone ever got, was Daystar, but they cancelled the Turbo 060 in favor of the Turbo 601. Unless Daystar's old work leaks, I don't expect an 060 accelerator to ever happen. Well, that and someone who had an 060 in their LC475... but with a custom ROM to run Gentoo Linux and Gentoo Linux only.

And, frankly, with FPGAs around, a custom core that implements all necessary 040 features while bringing the speed enhancements of a 060 would negate the need for actual 060s. It's not as if a real 060 would be more "authentic" than an FPGA, for those who care about that, because the 060 as said never came to the Mac.
 

Danamania

Official 68k Muse
Going back a long long way, but there were posts in the early 2000s of 060 to 040 adaptors working in only one model. One of the last 68ks, the LC/Quadra/Performa 630 series which was supposed to fire up OK with an 060, at least to the point of booting.
 

joshc

Well-known member
I guess you have to ask what you are looking for. If you want a faster Mac, buy a faster one. Apple never implemented 060 support and once the PowerPC Macs got past their first generation, performance blew the 040/060 away.
 

Daniël

Well-known member
Going back a long long way, but there were posts in the early 2000s of 060 to 040 adaptors working in only one model. One of the last 68ks, the LC/Quadra/Performa 630 series which was supposed to fire up OK with an 060, at least to the point of booting.

As in, it chimed, or it straight up booted into Mac OS? Was there any evidence provided? I still have a hard time believing anyone got this working, outside of the chap with his FrankenLC475 running Gentoo. And even then they didn't provide sufficient evidence to proof that thing actually worked.
 

Crutch

Well-known member
Regardless, the 060 is missing instructions that the Macintosh requires, so it won't work without somehow editing the Macintosh ROM.

Which instructions did they drop? I have not been able to find a really clear list anywhere.
 

Franklinstein

Well-known member
I read something about it ages ago but I don't remember specifics. It's a pattern though: basically with every major change since the '020, Motorola has compromised pre-existing features, instead opting for "compatibility" by emulating in software the features/instructions that were dropped. This is why the MMU built into the '030 is "compatible" with the 68851 (no idea what of significance to Macs was changed here, maybe nothing), why the FPU in the '040 is "compatible" with a proper 68882 (like fractals? the '040's FPU no longer has the transcendental instructions in hardware so they're going to be slow to draw), why the '060 is "compatible" with existing 68k systems (which is why you need either a low-performance '040 emulation mode and/or an emulation library loaded).
You may think that x86 chips did it better, but aside from keeping the ISA consistent, they really didn't: nothing was directly compatible outside of its immediate family, and those things that were (Pentium OverDrive for Socket 3, PII OverDrive for Socket 8) had been specifically designed to be. Socket 7 was probably the golden period of x86 drop-in compatibility, after which everything went back to being proprietary.
PPC chips were better in that basically all of them ran on the same ISA on the same 60x bus up to and including the full 750 and 74xx lines (though of course the 7400s could use the improved MPX bus but 60x was available as a fallback); it's just a question of cramming the chip into the existing board somehow.

Anyway along with Daystar, Interware was apparently also working on an '060 upgrade but they too gave up, not getting any further than designing a card for potential future use with the '060 (the Booster CV 40 cards have visible pads with traces run where an '060 socket would've gone).
 

olePigeon

Well-known member
I seem to recall reading about a Daystar employee commenting on the 060 upgrade they had started working on. After testing, it was concluded that it was significantly slower than PowerPC native stuff. While it may have been faster at native 68k versus emulated 68k on early PowerPC, Apple was already previewing 100+ MHz PowerPCs to developers. So there was little point in continuing to develop a 68060 accelerator. So they bypassed it and went directly to PowerPC accelerators.

However, that was then, when the future of the Mac and the businesses that supported it were forward thinking. But as a hobby now, I wouldn't mind a late revision 75MHz 68060.

Would be great if a former Daystar or Interware employee still had the schematics and support hardware for a 68060 accelerator so it could be cloned.

Edit: Not having an FPU would be painful, though.
 

dolek

New member
@joshc
I guess you have to ask what you are looking for.
I do it only for fun and because I can do it and just because. I like play with hardware by tweaking, overcloking, upgreading it, etc.
If you want a faster Mac, buy a faster one.
I don't need faster Mac, I've got PC. I'm only interested in 68k Macs and I choose 475 model because it is the fastest model in "pizzabox" (I like it). Other looks more like old desktop and tower PCs.

@Daniël
Well, that and someone who had an 060 in their LC475... but with a custom ROM to run Gentoo Linux and Gentoo Linux only.
It's interesting, where can I read more about it?
And, frankly, with FPGAs around, a custom core that implements all necessary 040 features while bringing the speed enhancements of a 060 would negate the need for actual 060s.
I agree that is good way but I don't know such projects. If You know that please share with it.

@Danamania
One of the last 68ks, the LC/Quadra/Performa 630 series which was supposed to fire up OK with an 060, at least to the point of booting.
Where can I find any info about it?

@Daniël
Regardless, the 060 is missing instructions that the Macintosh requires, so it won't work without somehow editing the Macintosh ROM.
Theoretically, according to MC68060 UM, if you fulfill all requirements from chapter called "Using an MC68060 in an Existing MC68040 System" it should work without ROM modifications. As I wrote earlier in my Amiga it works without ROM modifications and without loading special libraries, of course it recognize CPU as 68040 without FPU and run much slower.
 

Byrd

Well-known member
Hi dole
But as a hobby now, I wouldn't mind a late revision 75MHz 68060.

Get shocked for the prices of these - a "full" MMU/FPU higher clocked 68060 is either now unobtainium or $500+ in any currency. It's crazy.
 

Jockelill

Well-known member
Reviving this thread a little bit:)
I recently came across this:


They offer it also for A500 and A600, on the A500 you remove (the socketed) 68000 and plug the card directly to the cpu socket (sounds like a PDS doesn’t it 😉?!)

so, wouldn’t it be possible to port the 68080 (now not the 60) in the same way to all the PDS-machines?

I know that the amiga community in general is able to shell out more and I also get that there are tons of A500 and A600, but if such a card would be made with an LC PDS (hopefully fitting CC, LC, LC2, LC3 and LC475) it would quickly add up also to a lot of potential computers. I would definitely be prepared to pay 500ish for such a card. And if it was made for LC it could most likely also be made for the IIci, IIcx, IIvi and IIvx (but LC would probably be the largest customer base).

I’m thinking the best way would be a kickstarter campaign to fund such a project.
 

Daniël

Well-known member
If one had the time and the source code, sure, the "faux" 080 Apollo core could potentially be modified to work in a 68k Mac. It's just that I don't think the Apollo team would be particularly interested, and it's closed source as far as I know, so you'd have to start from scratch.

And whereas the Amiga community has a lot of diehards insisting on staying on that platform for more than just hobbyist tinkering in the spare few hours, the vintage Mac community really doesn't. That's mainly because the Amiga platform died (all modern takes on a new "Amiga" really are just third party attempts to imagine what Amiga could have become, had Commodore survived and done a similar architecture switch as Apple), and a lot of people never really managed to let go. The Mac, even through hard times, persisted, and eventually flourished again.

Where you want a faster Amiga than what Commodore offered, you need to go third party. Where you want a faster Macintosh than a specific 68k or PowerPC model, you can just buy a faster or newer architecture one. The Mac accelerator market today is as a result far more niche, which is why I doubt anyone would put in the effort to do for the Mac, what the Apollo Team did for the Amiga. That, and the potential interest in backing a Kickstarter being much lower.
 
Last edited:

cheesestraws

Well-known member
so, wouldn’t it be possible to port the 68080 (now not the 60) in the same way to all the PDS-machines?

This isn't reasonably going to work.

First of all, I'd note that the 68080 isn't a real Motorola microprocessor, it's some weirdy thing cooked up by the Vampire crowd.

Secondly, the existence of an accelerator (remember, in general, the 680x0 series are not true supersets of their predecessors) does not get rid of the problem of making the software and ROMs work. Nobody who has the skills to do this seems particularly inclined to do so, partly because:

The "politics" of accelerators is very different in the Amiga vs. classic Mac worlds. Many Amiga folks are fundamentally investing in their denial that their platform is a dead irrelevance. Classic Mac users cannot honestly have the luxury of that denial; that the world left the platform we enjoy using behind is just an undeniable fact. Modern Macs exist, three processor families removed, and the old ones, even with all they have going for them, are at best a curio, an antique, or a spur for nostalgia.

But Apple did make the jump between processor families, and if you want a fast classic Mac, that's kind of what PowerMacs are for. I'd hestitate to recommend building a new Takky now, given the increasing scarcity of working CCs, but they come up on Yahoo Japan reasonably often from back in the day. There are analogues to really all the 68k Macs in the PPC family. And most of those machines are at least adequate for purpose. If you just want to run 68k programs unreasonably fast, that's what G4s are for.

So anyone who was trying to manufacture this kind of thing for classic Macs would be essentially competing with every eBay seller who has a cheap G4 for a tenth of the price or less.

So, in the classic Mac world, I suspect the only reason to do this or anything like it would be pure engineering interest, and the way to go about it would not be to pick up an Amiga accelerator powered in equal parts by spite and denial. And nobody who has the engineering chops seems to be particularly interested in doing so.
 
Last edited:

Jockelill

Well-known member
Fair points, and yes, any G4 will run any 68k more than fast enough, but I still like the idea of what a modern accelerator could offer in terms of hdmi support, Ethernet, modern resolutions, sd drive etc. Since most people anyway use some kind of scsi to sd solution, it would be nice with just one card for all of it:). But I fully understand your points of why this would not workout.
 

joshc

Well-known member
We already have this on old Macs, either via PDS, NuBus or onboard Ethernet. Not sure why you need to put that on an accelerator or what that achieves?

modern resolutions
There are several period NuBus video cards which offer high resolution support. Some are not easy to come by, look out in trading post for them.

As for most of what you are looking to experiment with, may I suggest trying something that isn't a compact Mac? Something with NuBus or PCI slots is going to give you much more flexibility/power/expandability.
 

cheesestraws

Well-known member
but I still like the idea of what a modern accelerator could offer in terms of hdmi support, Ethernet, modern resolutions, sd drive etc

Yup, and I don't want to crap on people imagining things they'd like to do with their machines, because that's where the fun comes from. But sometimes it collides with reality, alas :(
 

Jockelill

Well-known member
Yup, and I don't want to crap on people imagining things they'd like to do with their machines, because that's where the fun comes from. But sometimes it collides with reality, alas :(
No worries, some things are not done for good reasons (which may not be known to everyone:)), but some times ideas needs to be explored anyway :)
 
Top