July 5th 2000
As I read again several questions at MSX list about Z380 Padial's board,
here I write some questions and answers:
1-
Question:
---------
" The 1KB common memory makes data transfer between Z380 and MSX slow ??"
Answer:
--------
No.
The 1KB memory is a very-fast memory that can be accessed at the same time
by MSX and by Z380.
So, while the MSX reads p.e. a 256 byte block, (using LDIR or similar)
The Z380 can write another 256 byte block in another starting address.
This way, the MSX is making continuously LDIRs, without waiting for the
Z380.
The same thing for I/O, ( OTIR instead LDIR )
Note that both CPU: Z80/R800 and Z380 works the same time, so, it is more
powerfull 2 CPUs than 1, not ?
2-
Question:
---------
Why Padial's Z380 card doesn't make old programs run faster ?
Why you have to make new software to use the Z380 ?
Answer:
--------
Making old programs run faster has only sense for "aplications".
For MSX, there are only a few aplications. Most are games.
Making games run faster has no sense, because they are VDP synchronized, and
if not, you cannot play a game 10 times faster than usual !
If you want to make old aplications run faster, you have to modify them
to run under Z380. (Note that it is easy, as Z380 is 100% Z80 compatible )
The main idea for the Z380 board is to make new 32-bit powerful software.
Some things are not possible at 8-bits, 64K, because huge data, and so.
Now, you haven't to use the mapper, as you can access linearly the Z380 Ram.
And a 18.4 MHz Z380 is several times faster than a 28.6 MHz R800 CPU !!
*Anyway, there is a way to replace the MSX internal CPU for the Z380
Padial's CPU: You have to modify a few your MSX. Then, the Z380 card halts
the Z80, and replace it.
This way, you have to work at 3.5 MHz instead 18.4 MHz, because MSX hardware
doesn't support high clock.
But 3.5MHz Z380 is from 2 to 6 times faster than a 3.5MHz Z80.
And you can access both memory: Internal MSX memory, and Z380 card linear
memory, the same time !
3-
Question:
--------
Why Padial's Z380 board doesn't include a VDP or Sound device?
Answer:
--------
Because Padial is making a separate VDP and a separate Sound device.
Making all in only 1 board is impossible, and too expensive to buy all.
For example, you can use a GFX9000 with Z380, at 18.4 MHz
(Using Padial's 32 bits slot-expander -like a motherboard for the Z380- )
The Z380 disconnect the expansor from MSX, and access GFX at higher speed.
About new Padial's development:
He's working on a very interesting Sound device:
By using DSP signal processors (very fast processors, for deal data)
you can hardware-emulate several MSX devices at the same time,
and even beter:
For example: PSG+SCC+FM+PCM+MModule+MSound+MIDI+.... are in
the SAME card !!!. You even can have 16 FM devices at the same time.
But it depends that people make the emulation program
( These DSP processors include a C compiler for this matters)
4-
Question:
---------
What about the new MSX ??
Answer:
--------
We all like a new MSX.
We wish they make a new one.
But we haven't any sure information about this.
That people doesn't ask world-MSX users what we would like for a new MSX.
The few news we have, it is like a new MSX 2+, but a bit faster.
Like a Turbo-R-Plus ??
We cannot be stopped waiting a magic new MSX appears.
They will make a new MSX for ... 10000 people around the world ??
What happens if nothing is created? several years lost ?
Anyway, the Z380 card is very interesting for all MSX users.
2 CPUs working at the same time in a MSX !!!
It is not a project. It is a fact !!! Several people have a Z380 card now !!
Who has a new MSX ??
We also apreciate other hardware projects.
We like FACTS, not WORDS.
Well, I hope this text has helped.
Excuse us, for not writting more about the Z380 card,
but we haven't time to write and program often, sorry.
Remind the LPE-Z380 web ( I will update it soon )
www.terra.es/personal/dzorita/lpez380.html
or the same, at:
http://teleline.terra.es/personal/dzorita/lpez380.html
Bye.
Daniel Zorita.
****
MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED]
and put "unsubscribe msx [EMAIL PROTECTED]" (without the quotes) in
the body (not the subject) of the message.
Problems? contact [EMAIL PROTECTED]
More information on MSX can be found in the following places:
The MSX faq: http://www.faq.msxnet.org/
The MSX newsgroup: comp.sys.msx
The MSX IRC channel: #MSX on Undernet
****
