23 Nov
2023
23 Nov
'23
10:31 a.m.
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