According to a chart in Microprocessor Report identifying the attributes of
all the major superscaler microprocessor chips available as of October, 1992,
only the Motorola 88110 had speculative execution.
Back in the sixties, I was working at IBM's Development Lab in Poughkeepsie,
NY when we (IBM) announced the IBM 360/91 - which one could argue was the
first computer that explored superscaler techniques (Of course, it was
definitely NOT a microprocessor ;-)
Of course, some CDC folks might argue with me on who was first :-)
BTW: I used the "Nancy" simulator (simulating 360 architecture) on the IBM
Stretch to develop an early diagnostic OS for the 360 - and for sure the
early 360's could not be considered superscaler - although I would argue that
Stretch itself was "close"...
Cheers,
Lyle
On Friday 14 November 2003 05:35, Eric Smith wrote:
I thought the
R4600 was, though maybe it was early 1994, but actually I
wasn't claiming any particular date
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. :-)
I meant the Pentium family.
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.
--
Lyle Bickley
Bickley Consulting West Inc.
Mountain View, CA 94040
"Black holes are where God is dividing by zero"