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You resort to assembler for critical operations or performance. Having a nice, clean orthogonal instruction set helps none of that. So while 68000 ASM may look

You resort to assembler for critical operations or performance. Having a nice, clean orthogonal instruction set helps none of that. So while 68000 ASM may look pretty and be easy to remember, its obvious why x86 won - you could get the critical jobs done.

tenebrisalietum 5y ago
I do know x86 for example has things like the STOS/STOSB/STOSW/STOSD which specifies a lot of behavior for a single instruction, and combined with the REP prefixes is a pretty elegant way to do memory block operations. I don't think 68000 had anything like that.
- JoeAltmaier 5y ago
  To be fair, Intel nerfed those instructions for a long time. See, DOS was using REPNZ STOSW for timing things. So as the processors got faster, those instructions didn't, so as to make DOS BIOS continue to operate correctly. It was a terrible time for x86. At the same time, I used a clever 12-byte sequence of those opcodes to swap software interrupt vectors on process switch. So each process could have its own floating-point exception handlers etc. We called it the 'soft vector chain' and it was among the least known parts of our kernel. A colleague (John McGinty) suggested in our old age we could consult by scratching our beards and saying "Ah! It must be the soft vector chain!" for every problem.
inkyoto 5y ago
> its obvious why x86 won - you could get the critical jobs done. It is a bit less obvious, in fact. Motorola never looked at 68k CPU's as a serious business, more like toying around with the CPU's all the time or looking at them as a less important spin-off of the main business. Their main sources of income were defence contracts (e.g. specialised or hardened microchips), microcontrollers, DSP's (which were pretty cool, by the way, – all implementing the Harvard architecture), memory chips (I think), radios and the field radio equipment and later mobiles. They carried largely the same attitude to 88k RISC and PowerPC CPU lines (albeit trying to compete more seriously for a while), but ultimately failing to catch up and leading to the eventual PowerPC demise. After that failure, they spun off anything CPU, DSP and microcontroller related into Freescale, and the rest is now history.

tenebrisalietum 5y ago

I do know x86 for example has things like the STOS/STOSB/STOSW/STOSD which specifies a lot of behavior for a single instruction, and combined with the REP prefixes is a pretty elegant way to do memory block operations. I don't think 68000 had anything like that.

JoeAltmaier 5y ago
To be fair, Intel nerfed those instructions for a long time. See, DOS was using REPNZ STOSW for timing things. So as the processors got faster, those instructions didn't, so as to make DOS BIOS continue to operate correctly. It was a terrible time for x86. At the same time, I used a clever 12-byte sequence of those opcodes to swap software interrupt vectors on process switch. So each process could have its own floating-point exception handlers etc. We called it the 'soft vector chain' and it was among the least known parts of our kernel. A colleague (John McGinty) suggested in our old age we could consult by scratching our beards and saying "Ah! It must be the soft vector chain!" for every problem.

inkyoto 5y ago

> its obvious why x86 won - you could get the critical jobs done. It is a bit less obvious, in fact. Motorola never looked at 68k CPU's as a serious business, more like toying around with the CPU's all the time or looking at them as a less important spin-off of the main business. Their main sources of income were defence contracts (e.g. specialised or hardened microchips), microcontrollers, DSP's (which were pretty cool, by the way, – all implementing the Harvard architecture), memory chips (I think), radios and the field radio equipment and later mobiles. They carried largely the same attitude to 88k RISC and PowerPC CPU lines (albeit trying to compete more seriously for a while), but ultimately failing to catch up and leading to the eventual PowerPC demise. After that failure, they spun off anything CPU, DSP and microcontroller related into Freescale, and the rest is now history.