I can't believe the paucity of comments on this article. Surely, this is of interest to HNers? Am I just the only one that's never heard of this? It sounds awesome, and confirms my personal bias that an Apple+Sun merger (prior to the Oracle acquisition) could have been terrific. We all complain about Apple's slipping quality these days, but they used to (?) have some amazing engineers.

Edited to add: Does anybody know why this got nixed? Would love to know the backstory to this.

This was canceled at the point where Apple needed to commit to spending a lot of money to implement the design in silicon. I heard it was canceled because upcoming COTS processors looked like they are going to be faster and cheaper. (Source: I worked in a different part of Apple ATG and was talking with some of the people on the project.)

I’m actually one of the architects of this processor. The story that I tell wasn’t so much that they were at the point of needing to spend real money, but it was pointed out that to compete with Intel/Motorola they would have to pay for development over and over- and the couldn’t afford (then) to spend the money to do that.

Ironically, that decision led (pretty much directly) to the formation of ARM (and PowerPC, of course)

1988 would put this squarely in the 'Apple trying to convince Motorola to develop the 88k' era, most likely this was a backup plan in case they failed (they did, but by the time the 88k was killed off, they'd managed to get AIM founded and the 601 was 'in the pipeline')

There was an AMD 29000 Macintosh. But Apple execs were afraid that would piss off Motorola too much, and they still needed their parts. So then there was an 88k Macintosh. Execs decided that Moro didn’t have the volume to compete with Intel, so they put them together with IBM to form AIM and develop PPC (they considered HPs Precision RISC as well) and went with that until it was clear even those two couldn’t keep up with Intel- or with Apples direction.

Was there any serious consideration for an ARM Macintosh derived from Mobius, or was that strictly meant as an Apple II replacement and then canned in favor of Newton?

I didn’t know that apple considered the M88K. I used DG Aviion servers with DG/UX, which were all multi cpu 88ks, and they were awesome, a staple of the industry I was in at the time (medical laboratories).

The rumor mill of 1990 has our back :) https://tidbits.com/1990/05/07/68040-macintosh/

Wow, now there's a name I haven't seen in a long long time... =)

I’m fascinated by this.

Hey, at least we know they had proper Plan B’s!

I see nothing else about this online, so this must be pretty recent public information

You should probably link to this instead: https://archive.org/details/scorpius_architecture

(This way has more compatibility with various computers and software that you try to view it. Also, for some reason the "FULL TEXT" link does not link directly to the file, nor does there seem to be a link from there as far as I can find, but if you change "stream" in the URL to "download" then it will access the file.)

Thanks for this. I couldn’t really read it on my iPhone otherwise

I disagree with that. You can hit "← Back to item details" to trivially get to the more information panel, while this presents content in a better way than linking to that link.

Coincidentally (or not?), Power Mac G5's later used the PowerPC 970MP (a dual-core part) which also carried the code name 'Antares'.

Really interesting architecture. The way they tried to make the processor units flexibly become SIMD or MIMD is thought provoking. Thanks for sharing this.

So... how soon can we expect a HDL implementation of this architecture? :)

The archive (seemingly erroneously) says this was created in 1989. The text itself, however, says it was from 10/88.

Did it have wicked glowing cooling rods?

https://farscape.fandom.com/wiki/Cooling_rod

What was it?

Late-1980s Apple’s plan for architecting their own RISC CPU. Never made it to production Macs.