> I have no idea if Padial implemented a memory mapper on his Z380 board,
but
> even if he didn't, who cares?
> If you want to run software that uses memory-mapping, just remove the Z380
> board from your cartridgeslot!!
And that is something I don't want to.
I want it permanently in my MSX... A bit like 7MHz.
Ofcourse with automatic hardware-specific timed slowdowns. (like on the
turboR, wait long enough when the MusicModule is being accessed, do not wait
at all when accessing the HD or memorymapper, wait 7 Z80 @ 3.5MHz T-states
when accessing I/O ports #98, #99 and wait 4 states when accessing #9A, #9B)
(btw, if the videochip is re-written the wait can be eliminated).
> Z380 is just as compatible as Z180 is, if not more! I still don't know if
> Z180 has IX/IY 8-bit access, but Z380 sure does!
> Z380 in Z80 mode has 64kB memory space just as Z80 has, registers are
16bit
> just as Z80, etc... It's fully Z80 compatible.
In that mode, Z180 is faster.
Btw, I don't really care if the Z180 or the Z380 is being used (as long as I
can also run the existing software in high-speed mode) (and as long as it
can directly access everything in 'enhanced' mode) (those are the
disadvantages of LPE's Z380 board to my opinion).
> > Z380 is faster than Z180 only in Z380 mode. AFAIK, in Z80 mode in Z380
> >is slower than Z180... and AFAIK the Z380 mode is not very compatible
> >with Z80.
>
> This is incorrect, Z180 is only faster than Z380 if run at a much larger
> clockspeed.
Fact is that there is a 33MHz version of the Z180 and only a 18MHz version
of the Z380 (14 MHz in LPE's design... why not use 60ns SIMMs or 100MHz RAM
and let it run at full speed??? I don't get it... waste of speed.)
> As for full Z380 mode not being very compatible, ofcourse, but
> full Z380 mode is only used on full Z380 programs. (duh)
I think you are right. The same goes for the Z180 ofcourse.
I prefer the ACE002 idea, but with a Z380 inside (at least if it can run at
max. speed in Z80 mode) (and as long as the speed difference isn't too
much).
I will not program Z380 specific. Most people won't I think. As said before,
it's a bit like the Gfx9000 (only 'worse'). Only a few people have it, and
if you write Gfx9000 specific soft, everybody without it can't run it. And
why the 'worse'? Well, the Gfx9000 is a real great expansion which adds alot
of extra features. The Z380-specific instructions are nice, but you can also
use Z80 code which might be a bit slower, but works on all MSX computers.
Surely, they make programming easier. But they can be worked around. Which
is also a reason why some people program Z80, because of the limits which
oppose a challenge.
The only advantage of programming specificly for the Z380 I see is the 4GB
adress range.
This does not mean I plead against the Z380. Only against Z380-specific
programming, and why we should rather look at speedup with the old
instruction set instead of a higher speed with a new instruction set. And
then always programs can be made which execute Z380 (or Z180)-specific code
when it is detected.
~Grauw
--
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visit my homepage at http://grauw.blehq.org/
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