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Ken Shirriff

A big computer architecture debate of the 1980s was RISC vs CISC, arguing that building Reduced Instruction Set Computers was better than Complex Instruction Set Computers like the 8086. Most instruction sets since then are much easier to decode than x86, but x86 keeps going.

8 comments
Ken Shirriff

I also have an interactive page to show which 8086 instructions generate particular Group Decode ROM outputs: righto.com/8086/groupRom.html

Wraithan

@kenshirriff the link goes to a 404 right now, maybe forgot to publish?

Roger

@kenshirriff I think the RISC v. CISC discussion needs to revisited with a benefit of historical hindsight. There’s a lot to learned about what makes architectures successful.

Ken Shirriff

@RogerShepherd Seriously, I think that technical merit has very little to do with the success of a computer architecture. Business factors and luck are much more important.

Brian Swetland

@kenshirriff I keep hoping it might still die out in my lifetime! Apart from archeology, I remain not a fan of its limited set of registers with various strange restrictions on usage, and absurd 1-15 byte instruction encodings. It brings me no joy. I mean, under the hood, Intel processors are translating this mess to something completely different and have been since, what, the Pentium era?

lopta

@kenshirriff Still a firm believer in RISC. I think @imorital was the first person to explain it to me.

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