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Comment by rebane2001

4 days ago

Why is the 8086 not equivalent to x86? PCLMULHQHQDQ is from the CLMUL extension, which only began appearing in CPUs in the early 2010s - are CPUs from before then not x86?

x86 is an overarching group. Each processor is backwards compatible, I believe, so a 486 can run 8086 code, but they are not equivalent. If I download an x86 version of a program, I don't expect it to be written only in 8086 instructions

  • When you download an x86 program you're making a lot of other assumptions too, such as what the target operating system and hardware are. Even 8086 MSDOS software won't directly work in this emulator because it's not emulating DOS nor an IBM compatible, it has it's own addresses for the I/O. It's still x86 though.