On Tue, 18 Apr 2000 21:24:28 +0200, Patriek Lesparre wrote:
>There are two points I would like to make here. The first:
>The calculations you perform are for a NOP or other simple instructions.
(...)
>(for EX instructions). But the Z380 gains speed on the more complex
>instructions, so that it's faster anyway.
>(BTW, I'm not sure what effect ROM/DRAM mode has on R800, does anybody know
>that?)
I don't know also. I just mentioned because I don't really know if something
changes when using DRAM mode. About the "extremely well very super ultra" opcodes
that Z380 has that are 30 times faster than Z80, hey, they exist. It's a fact.
Z180 also has opcodes a lot faster than Z80. But Z380 is NEVER faster than
1 instruction per 2 cycle. Of course, you will say me, oh! but Z380 has
prefetch! Yes, it has, but on "extreme slow situations" like OUTs this just
doesn't affect.
>And the second point is the most important one:
>Isn't the whole point of creating a new MSX, to support NEW software?
Maybe. What we are thinking will support new, but will support old ones.
>In that case it's not the performance of the Z80-compatible mode that is
>the most important.
If we will do a new computer, it's better do not support MSX at all.
Think, man! MSX is weird in several aspects. Why be stuck on these limitations?
Ademir is thinking on this "top most ever MSX" (ACE002) and also a NEW
whithou MSX limits computer (EduCAR). These are TWO different concepts.
Mix them will not bring us a good solution. Trust me. Ademir has been thinking
about this since 1987.
>It doesn't take a wizard to understand the Z380 is a FAR FAR FAR more
>powerfull processor than Z180, even if run on a lower clockspeed, if you
(...)
>16x16=32 bit MULTiply (7 times faster than R800!)
>16/16=16.16 bit DIVide
YES YES YES! But this are ALL NEW OPCODES! I SAID Z180 IS BETTER ON Z80 OPCODES
AND WE WANT A BETTER MSX, not a BETTER FRANKENSTEIN 32 BIT SLOT PCI COMPATIBLE
WITH SOME STRANGE CONCEPTION TO SUPPORT EVEN AMIGA AND ATARI ST OLD CARDS.
And, again, I just reported. The new board WILL BE ABLE to run with Z380
at full speed, but - again - have you asked yourself if the existent MSX
hardware support "this so fast Z380 new opcodes"? Have you thought that
your Z380 will do a 32 bit multiplay and stay waiting an eternity while
your PPI reads the keyboard lines? Well... these are some things we have
to THINK ABOUT. This is not just a matter of numbers, it's also a matter
of BACKWARD COMPATIBILITY. Why? Because if there is no backware compatibility,
it's not a MSX.
>The list goes on. Now also take in consideration the hugely expanded
>register set, there are 4 banks with each AF,BC,DE,HL,IX,IY and shadow
(...)
>speed penalty! Since the PC is 32bit the Z380 can access up to 4GB RAM
>without bankswitching!
Wow! And you think I doesn't know about this? Ademir WAS USING Z380,
but some day, when he ASSEMBLED the machine and put it to work he noticed
that Z380 HAD TO BE SLOWED DOWN to cope with MSX hardware. This is
THROW PROCESSOR POWER TO THE TRASH. This is something done frequently
on PC. This is NOT a good thing to do.
>I'm sorry if this message turned into sort of a rant or Z380 advertisment
>;) I just want to make clear the Z380 is the more superior CPU, even at a
>lower clockspeed. For me, using anything less than a Z380 for the next
>generation MSX hardware is NOT an option!
Is not an opinion when talking on a system WITHOUT LIMITS. Of course
EduCAR will use Z380, and not Z180. But this is not the case when talking
about MSX. Do it and you'll see what I'm talking about. I was the only
person, besides Ademir, that saw Ademir's Z380 board running. The processor
runs a lot, but the entire system... BLARGH! And note, even on a system running
at 33Mhz, the but frequency must be selected, because some hardware (most of
them) did not support anything greater than 3.57Mhz! Note, this is a
GREAT limitant.
As you can see, there is a lot more things to look forward than just
compare the processor power. From this point of view, my comparison is
as good as yours... (-;
Note, I'm NOT saying that Z380 is worst than Z180 (this would be insane!).
I'm just saying that, FOR USE ON MSX the Z180 is actualy better on overall,
not talking specifically about speed.
>Oh, by the way, that ADVRAM thingy sounds very cool :)
ADVRAM is the result of a hardware developer asking software developers
what would be great to implement on a new hardware.
Note that ADVRAM did not break MSX standard, but will change it a little.
Note 2: ACE002 will be able to run Z380 at any speed, as it's able to
run Z180 at any speed, and is able to run even Z80 at any speed. But
it'll be sold with a Z180 at 33Mhz.
And... if ACE002 see the sun light, I doubt that someone
do a Z380 at 18Mhz MSX faster (in overall, multimidia, etc, running
existent MSX - z80 - software) than the Z180 33Mhz MSX.
Remember: your VDP (9938/9958) runs at 10Mhz, PPI runs at 5Mhz, and
so on. Do not judge the computer speed because "this opcode is way faster!".
I'm talking about this because everyone said "Oh, Fray TR is smooth! Normal
Fray is messy!" and when I run normal Fray on my 7Mhz computer what I saw
was Fray TR without PCM. The speed is just the same. I know, in a 3D game
it can do difference... but then lets build a MSX TR board, plug it on
the PC and lets program the PC... Pentium III is VERY faster than Z380,
has MMX, superscalar processment, and so on. Z380 is trash compared to
PIII. (-:
AbraçOS/2, Daniel Caetano ([EMAIL PROTECTED])
...!m.tag
OS/2 Sites: http://www.quasarbbs.com/daniel/
http://www.geocities.com/SiliconValley/8752/os2hp/os2index.html
MSX Sites: http://www.fudeba.cjb.net/
Drawings: http://www.djgallery.tsx.org/
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