There's no challenge in naming a few parts that have speculative execution. In my original posting, I specifically stated that I couldn't think of any processors introduced before Nov. 1993 that had speculative execution, other than the IBM 7030 (Stretch, 1961). I wasn't claiming that there weren't any others, just that I didn't know of any. I was *almost* willing to claim that there weren't any microprocessors with speculative execution until after Nov. 1993. However, I may have been a bit hasty. Although I don't think the R4600 was out at that time, after thinking about it some more it occurs to me that some earlier R4K series parts may have had speculative execution, and probably the DEC Alpha (20164). So if I were the arbiter for geek points, I guess I'd have to give you at least partial credit. :-) Is there really a Pentium family? Aside from the Pentium Pro, Pentium II, and Pentium 3, which use similar cores, there seems to be little microarchitectural similarity between parts for which Intel uses the "Pentium" name. For instance, there seems to be more similarity between the i486 and Pentium cores than between the Pentium III and Pentium IV cores, despite the fact that the Pentium was superscalar and the i486 was not.