9 Dec
2005
9 Dec
'05
7 p.m.
On 12/9/2005 at 1:35 PM Allison wrote:
I added why it was faster. For the V20 in a XT clone it
was easily 10% and
for the V30 is was more..
Yes, but there the tech manuals and your explanation disagree. NEC seems
to think that the dual data busses were the big thing, but you mentioned
the EA calculation difference. Wonder which resulted in more performance
boost.
On the other hand there is a sorta improved Z80 like
thing NEC did, the
ucom7800 series and they are interesting. Looks Z80 like but the
instruction set is anything but. I have a bunch of the PIGGYback
(78PG11) and romless 7800 parts.
Just look at the Rabbit 2000 instruction set. "Sort of Z80" is the best
way to describe it. Many additions and deletions. Before I programmed it,
I had two choices--either sit down with the manual and carefully note
differences or program it in C, the way Rabbit wanted me to. Suffice it to
say that the level of binary compatibility would be a serious barrier to
getting Wordstar running, if that was one's intent.
Cheers,
Chuck