cclist at sydex.com
Thu Feb 23 01:54:46 CST 2006
I don't know if anyone remembers the speculation about the architecture of
Intel's first 16 bit PC back in the late 70's.
We had some teasers from Intel like "bigger addressing space" and "16 bit
registers" and "backward compatible with 8080 code".
My guess was that Intel would simply double the register sizes. Let's see
a->ax, check, b->bx, check, c->cx, check, d->dx, check,
e->ex, h->hx, l->lx (huh?). Well, okay, we did get SI and DI (but the Z80
has IX and IY as 16 bit regs, so no big deal). My other thought was that
registers would get paired up to form 32 bit address pointers (like hl, de,
and bc). Nope, we got the funny segment registers.
I was pretty happy about the improved register orthogonality (e.g. add
dx,bx), but the 8086 overall was a big letdown.
When the 68K was announced, my reaction was "Now that's the way it should
be done". I liked the NS 32016 even better. The Z8000 left me pretty
unimpressed, but less so than the 8086.
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