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Comment by fredoralive | Hacker News Reader

The argument is that 68k is "CISCier" than x86, the addressing modes in particular, so making a performant modern out-of-order superscaler core that uses it would be harder than x86.

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I believe in that. But Commodore could have plunked a cheap 68020 in their machines for backwards compatilibity (like how MSX2 had a SOC MSX1 inside, PS2 had a PS1 SOC, PS3 had a PS2 SOC, and so on) and put another "real" socketed CPU as a co-processor. Or made big-box machines with CPUs on PCI cards, for infinite expansion options. "True" multitasking, perfect for CAD, 3D rendering and non-linear video editing. It would have been very cool with an architecture where the UI could be rendered with almost hard realtime and heavy processing happened elsewhere.

This is almost exactly what the plan was, until C= went out of business:

https://en.wikipedia.org/wiki/Amiga_Hombre_chipset

It was going to be HP PA-RISC based and have an AGA Amiga SoC, including a 68k core.

How much of Hombre is myth-and-legend? Given how little progress with made with OCS->ECS->AGA, it seems unlikely they could even have built an Amiga SoC, nevermind designed a new 64-bit chipset.

Here's some stuff:

https://archive.org/details/Hombre_201808/Hombre_Presentatio...

Don't agree there considering x86 has MODRM, size-prefix(16/32 and later 64bit operand sizes), SIB(with prefix for 32bit), segment/selector prefixes,etc.

Biggest difference perhaps where 68000 is more complicated is postincrement but considering all the cruft 32bit X86 already inherited from 8086 compared to the "clean" 32bit variations of 68000 I'd make it a toss at best but leaning to 68000 being easier (stuff like IP relative addressing also exists on the RISC-y ARM arch).

Apart from addressing the sheer number of weird x86 instructions and prefixes has always been the bane of lowpower x86.

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