DOS ain't dead

Question about some x86 opcodes (Developers)

posted by mht , Wroclaw, Poland, 08.11.2008, 08:46

> Anyways, these days NEC chips are very very very rare, as even a 286
> outruns it.

Today XT machines are rare, in general. But some of them may still work

> The only "bug" commonly known for them is that "aam 16" etc.
> (i.e. with any operand other than default 10, since it was undocumented by
> Intel) don't work.

Too bad, "aam 16" and "aad 16" are handy for dec-hex conversions. I remember I had to revise some of my old code when I found this information. BTW, it is strange that they do not support it -- for me, the purpose of the second byte was obvious as soon as I noticed that this is a two-byte opcode (I had no "undocumented" documentation at that time). If NEC really reverse-engineered Intel chips, this is even more strange...

Complete thread:

• Question about some x86 opcodes - mht, 02.11.2008, 14:02 (Developers)
  • Question about some x86 opcodes - Japheth, 02.11.2008, 17:51
  • Question about some x86 opcodes - DOS386, 03.11.2008, 10:04
    • Question about some x86 opcodes - mht, 05.11.2008, 19:54
      • Question about some x86 opcodes - Rugxulo, 06.11.2008, 21:06
        • Question about some x86 opcodes - mht, 08.11.2008, 08:46
          • Question about some x86 opcodes - Rugxulo, 12.11.2008, 00:43
            • Question about some x86 opcodes - mht, 12.11.2008, 16:54
              • Question about some x86 opcodes - mht, 22.11.2008, 13:59