> 2- About a FlashRom for Z380 BIOS: It is dangerous !! If you program the
> BIOS and make a bug, maybe the Z380 will never run again because the bug.
> So, how can you correct the bug if you cannot use Z380 to re-program the
> FlashRom ??
> It is like PC FlashRom Bios trouble, and famous VIRUSES. The virus delete
> the BIOS memory, and you must waste the main board !!
> Well, you can use a removable FlashRom chip, but I don't know if it is
easy.
> Anyway, it will increase the price of the board, and can allow some non
> compatibility if people reprogram the BIOS by his way.
I have written something (in fact, a lot) about it, however it obviously
didn't arrive yet... Shit. I'll re-send.
For the moment, a small reply:
- Trust me, you won't have to be afraid of viruses in the MSX scene...
- About the incorrect BIOSes, I have supplied a solution for that
("FlashCart").
- A removable FlashROM chip... The only difference is that it is put in a
socket instead of directly soldered to the board.
- It will hardly increase the price, FlashROMs are very cheap.
- People who program their own BIOS should know it for themselves if they
want to be incompatible with the rest.
And one big advantage: you do not have to re-program the entire BIOS in one
time, and you can make adjustments and improvements later on. Hell, you can
even supply an old, 8-bits BIOS at first, and two years later end up with a
fully 32-bit enhanced BIOS!!!
> 3- About the comparisons from Z180 to Z380, I heard a lot of incorrect
> things from Z380. Please, read the Z380 information from Zilog's web
> www.zilog.com ) Documents are in PDF format.
I did yesterday and today. Thoroughly.
> 4- I think that the Z380 solves the MSX CPU limitations.
> The best feature, is the linear memory (32 bits to access it) because it
> allows to make long programs that deal with long data segments. Now, you
> don't need to map the memory like the Z80, using the memory map.
> At the same CPU speed, Z380 is double fast than Z80 executing the same
> instructions.
> This Z380 card is 14.3 MHz, so, it is similar to a Z80 at 28.6 MHz.
> And if you use 32 bits registers, you do the same things with half
> instructions.
I am >against< the LPE Z380 card as shown on the fair in Tilburg. It causes
much incompatibility. I DO like the Z380-as-motherboard (LP's third variant
in his previous message), and I think it can become really great in
combination with Ademir's new ACE002 MSX mainboard.
And I also strongly object against running at 14.3 MHz when the processor
has the potential to run at 18 MHz. This way, the difference compared to the
33 MHz Z180 is too big and people will choose the Z180 board because it's
just way faster than the Z380 board.
> I think that the Z380 instruction set is perfect to MSX.
> The only thing is that by now, the speed of 14.3 MHz is the only way of
> having a mid-prize board, but it is enough for MSX.
Will it really cost THAT much additional money to use faster RAM??? I doubt
it. And even if, then make an option to run at 14.3 MHz with slow RAM and to
run at 18 MHz with fast RAM... By the way, does the Z380 board use 16-bit
memory access??? Or does it use only 8 bits of its databus??? The Z380 has
the capability, you know, and it's not hard to do it at all (read the Z380
User's Manual chapter 9: Q&A).
> 6- Other thing: The "BOTH" mode of using the LPE-Z380 card: It doesn't
turn
> off the main MSX processor: That is, you use the Z80+Z380 or R800+Z380 at
> the same time.
> As the Z380 needs the MSX CPU to manage with internal I/O data, memory,
DISK
> Rom, and so, it is a very special way of working:
> -The main program can run on the Z380
> -The MSX CPU works as Hardware sever ( ports, MSX memory, Roms like
diskrom,
> keyboard, VDP, Vram, ...)
> So, it is a paralell working mode, in wich you add the both processor's
> power.
> This way, you can use the MSX hardware (like VRAM) at 100% because the Z80
> is 100% transferring data.
> If you use only 1 processor at the system, you will not use VRAM at 100%
> because the processor also must run the whole program.
That so-called 'dual processing' really sucks. It is totally non-upwards
compatible, and because of this it can't run older programs at high speed!!!
I expressed my thoughts about this in another mail before. If you'd like to
read it (if you not already had), I quoted it below...
~Grauw
> > OVER LPE-Z380-V2 card with MSX only.
> > OVER LPE-EVOLUTION4-V1 expansor with MSX only.
> > OVER LPE-Z380-V2 + LPE-EVOLUTION4-V1 expansor with MSX.
>
> Now you have three possibilities with one set.
> Since things written for the one can't be run on the other (you'll have to
> pull out and replug stuff), this is not a very practical setup. And basing
a
> future system on this is almost impossible, since you can't easily
'replug'
> things soldered on a mainboard.
>
> So I think it's better to use one of those three things instead of all
> three. The third (last) seems the best to me. If it is combined with
> Ademir's ACE002 to-be-released (resulting in some sort of ACE003LPE) you
> will have a very fine new MSX, with Z380 inside. I think that's a better
> goal to aim at than the current.
>
> Advantage is that it's a way better setup, it will be compatible with as
wel
> old as new soft, it is also set-up for the future and there won't be two
> concurring boards, which certainly won't do good to any of them, because
> then half of the MSX-ers will develop soft for the one, and the other half
> will develop for the other board.
>
> Also, the 1k SRAM is not needed anymore, and no difficult soft (???) to
> relay the I/O and an entire new BIOS and Basic have to be written anymore.
> That is, at first. When you put the BIOS in FlashROM, it can be updated,
and
> after the first release the BIOS can be gradually upgraded with Z380
> instructions and enhancements...
>
>
> ~Grauw
>
>
> btw, I have updated Ademir's email-adress...
>
>
> --
> >>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<
> email me: [EMAIL PROTECTED] or ICQ: 10196372
> visit my homepage at http://grauw.blehq.org/
> >>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<
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