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I still have some of the 88000 reference manuals, and it was really my first introduction to RISC architecture, and I thought it was great. But I never figured

I still have some of the 88000 reference manuals, and it was really my first introduction to RISC architecture, and I thought it was great. But I never figured out why companies like Apple never chose it for their CPU?

rbanffy 6mo ago
The 88000 was implemented across three large ICs. This took an enormous amount of board space and would be unfeasible on the smaller Macs.
shawn_w 7mo ago
Complicated, expensive CPU marketed to very high end workstation use? Nobody thought it was worth picking up even if it was faster than the alternatives.
- hrmtst93837 6mo ago
  [flagged]
  - panick21_ 6mo ago
    Exept of course that Apple internally spent outrages amount of resources on their own CPU project that also wouldnt have had a volume story. Its only because that procet failed that they started looking at alternatives.
mrpippy 7mo ago
I believe it was the first RISC that Apple prototyped building a Mac around, including a 68K emulator. IIRC from Gary Davidian’s CHM oral history, it was corporate dealmaking that led to AIM and PPC more than any technical negatives for the 88K. https://computerhistory.org/blog/transplanting-the-macs-central-processor-gary-davidian-and-his-68000-emulator/ https://computerhistory.org/blog/transplanting-the-macs-cent...
- klodolph 6mo ago
  Yeah, this is probably closest to the right answer. Apple DID choose the 88K, and then changed. Reportedly they put some 88K systems in a Mac chassis. I do wonder what the exact reasons were. Maybe the PPC (complete systems) could be made cheaper? Maybe Apple was worried about relying on a single vendor? I am kind of skeptical of the “corporate dealmaking” angle, because it seems like there are valid technical reasons to NOT choose the 88K. Namely, that it requires companion chips, and the whole system (board + chips) ends up being complicated and expensive.
  - kalleboo 6mo ago
    What I always read was that Apple did not want to be stuck relying only on Motorola again like they were with the 680x0. And it worked out, kinda, Apple had IBM to rely on to make the G5 (until IBM also lost interest) I remember reading that the successor 88110 design with the support chips integrated was announced mainly to woo Apple but I don't know how true that is.
    - fredoralive 6mo ago
      Bitsavers have some documents about the Jaguar RISC project[1] that do indicate Apple's feedback went into the 88110, for example in the System ERS it states "The main processor for the Jaguar is a new version of the Motorola 88000 family which has been enhanced (with input from Jaguar's team) in several areas over the existing implementation. This processor (which will be the MC88110) will be referred to as XJS in the ERS.". There's also an architecture document describing changes Apple wants to make to the 88000 ISA, although I'm not sure how much of this actually got through into the final 88110 (Apple wanted to break binary compatibility, not sure if that happened). [1] The high end RISC machine project that went nowhere, which AFAIK became known as Tesseract when switched to PPC before it fizzled out.
kev009 7mo ago
Timing. The 68k still had legs, i.e. the 68040 provided great drop in performance and had an enormous ecosystem and economies of scale. By the time the RISC wars were starting to get fever pitched, the POWER architecture and AIM alliance seemed like a blessing to combine ecosystems and economies of scale for the A and M constituents. And it was.. successful product lines for 2-3 decades from all sorts of embedded systems to G5 workstations to spacecraft.
cmrdporcupine 7mo ago
Both Apple and NeXT had machines prototyped around it, but it was initially very expensive I believe, and I think Apple was easily convinced to go with PowerPC ... and rather than evolve it and push it further Motorola dropped it in favour of going in on PowerPC. The sad thing is Intel showed there was still life left in CISC, and Motorola themselves ended up circling back on 68k in the form of ColdFire which proved you could do for 68k what Intel did w/ the Pentium. But by then all their 68k customers had moved on from the 68k ISA.
- p_l 6mo ago
  68k was much harder to optimize than x86, being way more CISC-y 68k like VAX was seen as dead avenue not only compared to RISC
  - Someone 6mo ago
    > 68k was much harder to optimize than x86 Harder to optimize or because of its orthogonal instruction set easier to write code for?
    - rjsw 6mo ago
      What matters is how easy it is to create an out-of-order implementation of an ISA, there isn't a 680x0 equivalent of the Pentium Pro.
      - wk_end 6mo ago
        Well, there's the 68080 - the modern FPGA-based 68k chip designed as an upgrade for Amigas - but that did arrive quite a bit too late. http://www.apollo-core.com/index.htm?page=features http://www.apollo-core.com/index.htm?page=features
      - cmrdporcupine 6mo ago
        ColdFire was/is literally that is my understanding. But there was really no market for it. They produced variants up to 300mhz if I recall but then relegated it mostly just to microcontroller market and then stopped developing it. It was too late, and just oh-so-slightly incompatible with 680x0. But I suspect if the ISA used in ColdFire v4 had existed in 1994, 1995 that perhaps Apple's honestly disastrous foray through PowerPC could have been avoided.
panick21_ 6mo ago
They did basically. What happened is that Apple own CPU project crashed and burned. Then they had some meetings with people including DEC for Alpha and IBM. IBM offered POWER and IBM was also willing to go in on some other projects, like the next gen OS Teligent. But Apple didn't want to drop Motorola fully. So Motorola, Apple and IBM figured out that with some tweaks to the 88000 the could turn it into something POWER like. And that thing was PowerPC that Motorola supplied to Apple. That's my understanding.

rbanffy 6mo ago

The 88000 was implemented across three large ICs. This took an enormous amount of board space and would be unfeasible on the smaller Macs.

shawn_w 7mo ago

Complicated, expensive CPU marketed to very high end workstation use? Nobody thought it was worth picking up even if it was faster than the alternatives.

hrmtst93837 6mo ago
[flagged]
- panick21_ 6mo ago
  Exept of course that Apple internally spent outrages amount of resources on their own CPU project that also wouldnt have had a volume story. Its only because that procet failed that they started looking at alternatives.

mrpippy 7mo ago

I believe it was the first RISC that Apple prototyped building a Mac around, including a 68K emulator. IIRC from Gary Davidian’s CHM oral history, it was corporate dealmaking that led to AIM and PPC more than any technical negatives for the 88K. https://computerhistory.org/blog/transplanting-the-macs-central-processor-gary-davidian-and-his-68000-emulator/ https://computerhistory.org/blog/transplanting-the-macs-cent...

klodolph 6mo ago
Yeah, this is probably closest to the right answer. Apple DID choose the 88K, and then changed. Reportedly they put some 88K systems in a Mac chassis. I do wonder what the exact reasons were. Maybe the PPC (complete systems) could be made cheaper? Maybe Apple was worried about relying on a single vendor? I am kind of skeptical of the “corporate dealmaking” angle, because it seems like there are valid technical reasons to NOT choose the 88K. Namely, that it requires companion chips, and the whole system (board + chips) ends up being complicated and expensive.
- kalleboo 6mo ago
  What I always read was that Apple did not want to be stuck relying only on Motorola again like they were with the 680x0. And it worked out, kinda, Apple had IBM to rely on to make the G5 (until IBM also lost interest) I remember reading that the successor 88110 design with the support chips integrated was announced mainly to woo Apple but I don't know how true that is.
  - fredoralive 6mo ago
    Bitsavers have some documents about the Jaguar RISC project[1] that do indicate Apple's feedback went into the 88110, for example in the System ERS it states "The main processor for the Jaguar is a new version of the Motorola 88000 family which has been enhanced (with input from Jaguar's team) in several areas over the existing implementation. This processor (which will be the MC88110) will be referred to as XJS in the ERS.". There's also an architecture document describing changes Apple wants to make to the 88000 ISA, although I'm not sure how much of this actually got through into the final 88110 (Apple wanted to break binary compatibility, not sure if that happened). [1] The high end RISC machine project that went nowhere, which AFAIK became known as Tesseract when switched to PPC before it fizzled out.

kev009 7mo ago

Timing. The 68k still had legs, i.e. the 68040 provided great drop in performance and had an enormous ecosystem and economies of scale. By the time the RISC wars were starting to get fever pitched, the POWER architecture and AIM alliance seemed like a blessing to combine ecosystems and economies of scale for the A and M constituents. And it was.. successful product lines for 2-3 decades from all sorts of embedded systems to G5 workstations to spacecraft.

cmrdporcupine 7mo ago

Both Apple and NeXT had machines prototyped around it, but it was initially very expensive I believe, and I think Apple was easily convinced to go with PowerPC ... and rather than evolve it and push it further Motorola dropped it in favour of going in on PowerPC. The sad thing is Intel showed there was still life left in CISC, and Motorola themselves ended up circling back on 68k in the form of ColdFire which proved you could do for 68k what Intel did w/ the Pentium. But by then all their 68k customers had moved on from the 68k ISA.

p_l 6mo ago
68k was much harder to optimize than x86, being way more CISC-y 68k like VAX was seen as dead avenue not only compared to RISC
- Someone 6mo ago
  > 68k was much harder to optimize than x86 Harder to optimize or because of its orthogonal instruction set easier to write code for?
  - rjsw 6mo ago
    What matters is how easy it is to create an out-of-order implementation of an ISA, there isn't a 680x0 equivalent of the Pentium Pro.
    - wk_end 6mo ago
      Well, there's the 68080 - the modern FPGA-based 68k chip designed as an upgrade for Amigas - but that did arrive quite a bit too late. http://www.apollo-core.com/index.htm?page=features http://www.apollo-core.com/index.htm?page=features
    - cmrdporcupine 6mo ago
      ColdFire was/is literally that is my understanding. But there was really no market for it. They produced variants up to 300mhz if I recall but then relegated it mostly just to microcontroller market and then stopped developing it. It was too late, and just oh-so-slightly incompatible with 680x0. But I suspect if the ISA used in ColdFire v4 had existed in 1994, 1995 that perhaps Apple's honestly disastrous foray through PowerPC could have been avoided.

panick21_ 6mo ago

They did basically. What happened is that Apple own CPU project crashed and burned. Then they had some meetings with people including DEC for Alpha and IBM. IBM offered POWER and IBM was also willing to go in on some other projects, like the next gen OS Teligent. But Apple didn't want to drop Motorola fully. So Motorola, Apple and IBM figured out that with some tweaks to the 88000 the could turn it into something POWER like. And that thing was PowerPC that Motorola supplied to Apple. That's my understanding.