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M68k Compatibility Card?

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Raven

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Once again, I begin a thread referring to the title with "do these exist?".

It would be cool to do the reverse of a DOS compatibility card and run Mac OS 6 or 7 on a PC in a window under 95 or 3.1, or run it full-screen on top of DOS.. No reason why these can't exist, but do they?

(And yes, I know about Mini vMac, but emulators just feel like cheating to me... Can someone convince me otherwise? That would be convenient..)

Edit: I've partially answered my own question. Apparently Gemulator (intended to emulate the Atari ST, but also capable of old Mac apparently) had a hardware accelerated board for older machines to use, so conceivably you could get hardware-accelerated emulation of old Mac this way using vMac or Mini-vMac (I think the former, can't remember which one I read it on). Are there any other boards, though, and am I correct on this?
 
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Raven said:
Once again, I begin a thread referring to the title with "do these exist?".

It would be cool to do the reverse of a DOS compatibility card and run Mac OS 6 or 7 on a PC in a window under 95 or 3.1, or run it full-screen on top of DOS.. No reason why these can't exist, but do they?

(And yes, I know about Mini vMac, but emulators just feel like cheating to me... Can someone convince me otherwise? That would be convenient..)

Edit: I've partially answered my own question. Apparently Gemulator (intended to emulate the Atari ST, but also capable of old Mac apparently) had a hardware accelerated board for older machines to use, so conceivably you could get hardware-accelerated emulation of old Mac this way using vMac or Mini-vMac (I think the former, can't remember which one I read it on). Are there any other boards, though, and am I correct on this?
Click to expand...

Oh, there were lots of boards with 68000 that could fit in a PC. How about http://books.google.com/books?id=7i8EAAAAMBAJ&pg=PA11 ? Predates the Mac so its awesome. But making physical hardware that would successfully fool Mac software will be quite challenging. I am lazy and will stick with Mini-vMac. With reasonable amounts of cache, it flies.
 
Ah well yeah if I use Mini vMac I can make the virtual Mac go so fast that the question mark pre-bootup blinks fast enough to be the refresh rate of a monochrome CRT. I just hate cheating..
 
Hi! I would love to make a 68K CPU board for either S-100 or ISA someday. That would be cool and a dream of mine for a long time.

Achieving Mac compatibility is probably next to impossible as the closed architecture corporate drones at Apple saw to that. I was a big Apple II fan "back in the day" and recall the horror when I saw first saw the Lisa and then Mac were practically hermetically sealed closed architecture. No expansion bus, few real programming tools, no bus monitor or NMI vector boards, proprietary ROMs with no published sources, it required specialized tools to even open the case, etc. Gee, what a let down and it made the IBM PC a whole lot more appealing -- especially those cheap Taiwanese clones. :-(

There were a number of 68K S-100 boards as I recall so it is not impossible. As John and I work through the S-100 board list maybe we'll get to a 68K board after working through the Intel units. A ISA 68K or modern derivative based on ColdFire would certainly be possible were there enough interested parties. Probably run CP/M-68K or NetBSD or other 68K OS though.

Thanks and have a nice day!

Andrew Lynch
 
68K seems so--ordinary. I've got a 68020 Palantir card that was used for OCR and haven't done a thing with it.

I'd like to see a NS32032, Clipper, MicroNOVA or some other uncommon CPU on an ISA/PCI card.
 
There were no such cards that I have ever heard of.

As you've found, there are software emulators of the Apple hardware. There was even "Executor" which was an OS-level emulator; didn't require a Mac ROM, it was a pure reverse-engineering of the Macintosh Toolbox and OS API. It's *VERY* limited, though; in that it only emulates a 68000 CPU, and can only run a rather limited set of programs, with decent support for programs that run in System 6, and a smaller set of SYstem 7.0-capable apps.

Even sanctioned clones were very rare up until the infamous "clone years" of the mid '90s. There were only two "allowed" clones before that. Both were companies that purchased off-the-shelf Apple hardware and modified them; thereby not violating any Apple rights. Only one of the two even did anything impressive. Outbound produced true "laptops" years before Apple, from Macintosh Plus motherboards. Later, they made one from the SE/30. The second company just took a stock IIfx, overclocked it, and threw it into an insanely large tower chassis.

There was a Mac ROM board for the Atari ST that would allow you to put your Macintosh ROM chip into your Atari ST, then run software that would bootstrap the Mac OS. That's about as close as it got to a "Macintosh compatibility card". (I think there are a few similar cards for use with software emulators, to make them "legit".)
 
One thing that really annoys me about Mini vMac is that you can't properly full-screen it. You can make it "full screen", in which it places a huge black border around the same sized window, and you can "zoom" which makes it twice as big. There is no way to stretch the image to fill your screen, and I see no reason that they can't make the emulator scale nicely, or even have native resolutions for a modern screen (unless software would choke on that).

How about a PPC card? Run PPC Mac from 7 through OSX without emulating would be pretty awesome.
 
Hi! PPC is an unlikely possibility but Mac OS compatibility is an absolute non-starter IMO. Even the earliest versions of PPC were large SMT devices and certainly not amenable to home brew style projects. Don't get me wrong, PPC is awesome but not suitable for home brew due to the technologies involved.

You can thank Apple Inc for killing any hope of a Lisa/Mac open hardware and/or clone community. They also killed off anything approaching open hardware and even a hint of home brew style computers. There were some hackintosh like systems kicking around but as I recall Apple Inc even went after them since they used surplus Mac motherboards and ROMs. What a shame and total heartbreak. Starting a home brew project with Mac emulation as a goal is just an invitation for a Apple Inc lawsuit. They are not a friendly bunch to deal with. It seems to me a weird double standard that MS gets universally demonized in the press while Apple Inc gets a pass. Apple Inc is every bit the mega corporation MS is -- almost entirely closed and proprietary.

I can't think of a single PPC home brew project. 68K, Coldfire, or some of the less common CPUs that Chuck mentioned are at least possible. I recall the NS32032 kicking around for a while in the mid 1980's but not much since. I wouldn't stray out too far WRT exotic CPUs though as available tools diminish quickly. The 68K maybe boring but at least there is CP/M-68K and NetBSD for it. There are probably other less common open/free OSs available too.

A 68K S-100 board is probably possible and maybe an ISA version assuming no backward compatibility requirements. I've seen home brew projects I think would fit on a Eurocard although those typically used 68008 CPUs.

Thanks and have a nice day!

Andrew Lynch
 
The only Mac emulators (hardware) that I have seen seem to be Amiga based. Macs needed to run DOS/Windows so there are tons of cards for that, few PC's needed to run mac so nothing was done.
 
What, didn't anyone use Magic Sac with their Atari ST? It was pretty cool for the time.

Bill Godbout (Compupro) had an S100 68K card and there was at least one NS32016 ISA card.

And there were 68K motherboards with ISA buses that fit in XT cases.
 
Chuck(G) said:
What, didn't anyone use Magic Sac with their Atari ST? It was pretty cool for the time.
Click to expand...

That's it! That's what I meant by "ROM board for the Atari ST"

Chuck(G) said:
And there were 68K motherboards with ISA buses that fit in XT cases.
Click to expand...

Along this line, there was "Mac-On-Linux" for PowerPC Linux boxes. One could throw a PowerPC dev board in, (there are/were PCI add-in cards with a PPC on them,) get Linux up and running on the dev board, and run MOL on it.
 
Hi! Yes, its the CompuPro and Cromemco 68K S-100 boards I recall. There was a brief discussion on CCTALK a few months ago on the topic.

68K S-100 seems the most practical option although I think it could be extended to ISA also -- especially if CP/M-68K is the target OS. NetBSD is cool too but as I recall it requires an MMU and other logic since it is *nix-like. Also, I think the NetBSD 68K port requires a full blown 32 bit CPU meaning the target would have to be 68020 or later but I could be wrong on that. 68020 + MMU starts to be a pretty tall order for ISA and even S-100.

Anyway, I am not familiar with 68K design so this remains firmly in the realm of fantasy land but if anyone wants to give it a go count me in for schematics, PCB, and prototyping support.

Thanks and have a nice day!

Andrew Lynch
 
Hi! Just out of curiousity does anyone know of any home brew ISA bus 68K boards? I've seen numerous home brew 68K projects of varying styles but none meant to plug into the PC/AT ISA bus. I tried Google but nothing obvious turned up. Ideas/URLs appreciated.

Thanks and have a nice day!

Andrew Lynch

PS, something like this but with more detail http://john.ccac.rwth-aachen.de:8000/as/pcpar.html
 
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Hi! Would any of our German/European vintage computer colleagues have access to the 1989 "mc" computer article containing the PC Par 68000 article? If so would you please scan it and post someplace or email a copy to me?

It turns out there were a few 68K ISA boards but nearly all were commercial as far as I can tell. There are some 68K home brew projects posted but few that seem genuinely "hobbyist friendly". That's a shame since 68K is a wonderful CPU but it didn't seem to share the home brew enthusiasm that simpler 8 bit CPUs enjoy like Z80, 6809, 6502, etc.

Thanks and have a nice day!

Andrew Lynch
 
Why all the obsession with making such a 68K ISA card Mac-compatible? The most interesting 68K-based platform back in the day was the Amiga. An Amiga compatible 68K ISA add-in card, now that would be an interesting project. :) Unfortunately, as well-documented as the original Amiga hardware architecture is, there is still no open source or even free-as-in-beer alternative for the proprietary Kickstart ROM. And you'd still need that for true software compatibility. :(
 
Hi! I think a 68K ISA board is practical depending on how complex it is. A simple non-bus mastering 68K ISA board with a simple dual latch communication link is within the realm of possible. Especially with a relatively simple OS like CP/M-68K or a 68K debug monitor.

A Mac or Amiga backward compatible unit is impractical IMO. Way too complex to design, much of the hardware and key software is proprietary and/or secret. Reverse engineering is simply not possible without massive effort probably requiring some form of corporate support. Also without special clean room reverse engineering techniques any one who tried would likely be sued by the IP owners. It would be as much of a legal hurdle as a technical one.

That being said, I think it is worth exploring a generic 68K ISA board. Thanks and have a nice day!

Andrew Lynch
 
Hi! I think I've found a good candidate for a 68K SBC. I've contacted the author and have permission to go ahead and make a PCB.

http://chaokhun.kmitl.ac.th/~kswichit/68k/68k.html

My plan is to just reimplement this design on a ISA prototyping board with two minor modifications. First, replace the CPLDs with their generic TTL equivalents. Based on the schematic this should add about 10 chips or so. Second is to add a bidirectional latch to the SBC so it can communicate over the ISA bus.

It may be the design needs some tweaking to allow for better resolution of the memory address for the IO. It appears that the MC6850 has a very broad address range and that is kind of wasteful. Some glue logic could narrow that down considerably.

While the SBC would be mounted on an ISA board and fit in a PC or AT bus computer, I am thinking to keep the voltage regulator so the board could operate as a standalone also. It is kind of a weird format but would make a neat SBC even just plugged in to a 9VDC "wall wart"

Who else would be interested in a 68K on an ISA board project? I'd like to gauge if there is any interest for a broader project or if this would be just something for a few N8VEM builders.

Thanks and have a nice day!

Andrew Lynch
 
I'd certainly be interested in some sort of 68k SBC. Have been toying with the idea for a while and was considering something like a 68k, 2x 6850, 256k - 512k RAM, IDE and a basic graphics output along the lines of what is described here...

http://elm-chan.org/works/crtc/report.html

I believe Apple has just released early source code for QuickDraw.....Hmmmm :)
 
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