Well, just to throw this into the conversation:
Over this past summer, I was studying the SCAMP (
)
In that collection I came across a very early printing of the PALM
instruction set, with the cover page dated March 21, 1972 of the printing,
and on the next page a date of March 16, 1972 of the document number. My
photos of that document is here:
We can't infer from this on when the actual PALM processor was developed
(which took place in or around Boca Raton, FL). We can only say this
description of the instruction set was published in early 1972, and we know
it was "fielded" (used in the SCAMP prototype) by September 1973 in a
fully functional "desktop computer" (though despite the sleek case, it was
still a "rough around the edges" prototype). Isn't the March 1972 date is
at least earlier than the Intel 8008 ? Also, digging through the Joe
George tech journal, I believe I recall a reference in those pages that
IBM's internal parts cost of the PALM processor itself was around $200-$300
(that being in 1973/1974 dollars) [at least a couple pages, Joe itemized
component parts, since they had specific cost goals to stay under]
As others have suggested, the idea of a microprocessor was very much in the
air, as an idea whose time had come. Recall the story that Datapoint was
"begging" Intel to make a processor, but Intel essentially cost Datapoint a
year since Intel was plenty happy selling the very profitable memory chips
(but also that TI's alternative didn't work out).
Now, of course an argument is then is PALM a microprocessor? Perhaps not
by todays standards and expectations, as it is a series of about 14
"Dutchess" chips, which is claimed to consist of MOSFET. I'm not enough
of
a hardware person to really argue on the nuance of the specific technology
involved inside there. But as I understand, neither of the 4004 or 8008
did much on their own and still needed quite a few chips to make a viable
system.
Anyhow - I'm not suggesting the PALM was special or particularly
innovative, but it did have multiple sets of 16x 16-bit registers (which
were referenced using memory addresses 0-128, but they were physically "on
the CPU board" itself) - which is interesting since the "many registers"
is
the path Intel went (in contrast to processors like 6502, 6809). The
System/3 before all this also had "memory mapped registers" (which I don't
know enough about that system to know if they were "memory mapped" like
PALM were, in that they were physically on the processor; or were they
"memory mapped" in like how 6502-based systems reserve R0-R16 in their
zeropage?).
-Steve
On Thu, Nov 23, 2023 at 4:31 AM Christian Corti via cctalk <
cctalk(a)classiccmp.org> wrote:
On Wed, 22 Nov 2023, Fred Cisin wrote:
An absurd argument:
It could be argued that the 8085, rather than being designed from
scratch was
simply a modification of the 8080. Perhaps
significant modifications,
but
nevertheless modifications, not redesign from
scratch.
8080 and 8085 are essentially the same (from the programmer's view).
If we accept arguments such as that, then we
could argue that Pentium is
a
modified 80486,
which is a modified 80386,
which is a modified 80286,
which is a modified 80186,
which is a modified 8086,
...
all the way down to the 4004 :-)
Right, this is what I always say.
BUT the cut is with the 8008. The 4004 is a completely different beast
and has absolutely no ressemblence to the 8008, e.g. Harvard vs.
Von-Neumann architecture etc.
The "modifications" (or better: heritage) can be seen if you look at the
registers. Initially A, B, C, D, E, H and L, they were the same in the
8080. When going 16 bits, they were "extended", i.e. called A extended, B
extended and so on, with names AX, BX, CX, DX, and the addition of
segmenmt registers. Later, when going to 32 bits, Intel already "forgot"
what AX stood for, and so they called the registers "extended A extended"
(EAX) and so on.
Therefore, it could be argued that Win11 can be
run on a "heavily
modified
modified 4004"
8008, not 4004.
Motorola tended to redesign from scratch, whereas
Intel would modify
their
previous design.
Yes, but that is a widely known fact.
[I warned you that it was absurd]
It isn't absurd at all, or not more absurd as my post ;-)
Christian