> And so is a PentiumPro and a PII, AFAIK. Though there are some differences in > instruction sets, so I don't know if for kernel purposes things as far back > as a PII will actually run a 686 kernel. They will. You need a pentium pro or instruction set compatible processor. Due to a gcc/intel disagreement you also need the "cmov" instruction. This is present on all Intel processors from Pentium Pro onwards, AMD Athlon and onwards and other current chips.