MIX is a 6-bit/2-digit hybrid binary/decimal sign-magnitude machine, typical of 50s-60s machines. MMIX is a 64-bit binary big-endian RISC with 256 windowed registers that resembles a hybrid of SPARC and MIPS, with all the traits of that 90s "RISC dream" that never really went anywhere.
If he were to design it today, it would probably look more like a mix of x86 and ARM.
> If he were to design it today, it would probably look more like a mix of x86 and ARM.
Why bother basing a new architecture on x86 when it's generally considered the worst ISA in history (with some boosting TI's TMS9900 instead)?
x86's advantage is basically its continuous dominance and compatibility with itself which managed to thwart even its original designer's attempt to displace it[0], but you won't get that by basing a new incompatible ISA upon it, so there's really no point in doing so.
> What matters is all the infrastructure around the instruction set, and x86 has all that infrastructure... at a lot of different levels
> I’ve been personally pretty disappointed with ARM as a hardware platform, not as an instruction set […] As a hardware platform, it is still not very pleasant to deal with.
And this is a lesson he learned: while originally interested in the Acorn Archimedes (which wasn't a great success) he went with the Sinclair QL (which outright failed) and…
> Finland wasn’t the center of the universe back then, after that, I learned my lesson: never ever go buy into something that doesn’t have infrastructure.
If I were designing something today, something clean, I'd give a really good look at just cleaning up x86_64. AMD64 did some of that.
What is RISC-V but a cleaned up RISC, omitting the architectural mistakes of previous RISCs (branch delay slot (MIPS), register windows (RISC-1), tagged integers (SPARC), ...). It has a place.
A cleaned up x86 would definitely have a place. The idea of parsing a CISC instruction and translating+caching the result as a micro-op has worked, flat out worked. Worst ISA in history? I think not. Most successful ISA in history.
Still, Intel really needs to do what ARM has done. Clean up their act. Itanium was changing their act. It kinda reminds me of the scene in Spinal Tap where they introduced the new direction. Intel just needs to get rid of their cruft, seriously needs to get rid of their cruft because ARM is a threat and ARMv8 is a weapon. The x86 tax helps prevent competitors in their space (as per their threats to Microsoft) but ARM isn't in their space; they're next door.
MIX is a 6-bit/2-digit hybrid binary/decimal sign-magnitude machine, typical of 50s-60s machines. MMIX is a 64-bit binary big-endian RISC with 256 windowed registers that resembles a hybrid of SPARC and MIPS, with all the traits of that 90s "RISC dream" that never really went anywhere.
If he were to design it today, it would probably look more like a mix of x86 and ARM.