"Due to the complexities of the 8086’s arbitrary-length instruction decoding and flags, 8086 instructions are first converted to a simpler intermediate format b

"Due to the complexities of the 8086’s arbitrary-length instruction decoding and flags, 8086 instructions are first converted to a simpler intermediate format before being executed. This conversion, along with instruction lengths and how each instruction modifies the flags, is assisted by some lookup tables which form part of the BIOS binary." I agree regarding the BIOS, but this sounds like the BIOS image contains "microcode" necessary for the emulator to run, which would seem to be cheating just a little.