Hi you all..!
>
> HARDWARE PROPOSAL:
> ------------------
> In stead of building an internal 3.58MHz clock in all SCC's, Audio's and
> Musics it would be convenient to have a fixed 3.58MHz clocksignal
> available on the cartridgeconnector and also a 'BUSCLOCK' which reflects
> the processor's speed. My proposal is to use pin16 for this (currently
> 'Reserved')
The idea is excellent....I had it some 3 years ago, BUT:
There's no way you can 'standardise' this somehow. No matter what
reserved cartridge-pin you take, or what signals you put on them,
you'll always have the same problem:
You'll have to modify SOME cartridges to work in a modified machine,
or some modified cartridges won't work in non-modified machines,
and/or some non-modified cartridges won't work in modified machines.
You might try and fix this for some of the most common cartridges,
but this problem remains. And you will all know how many different
hardware add-ons there are for MSX. If you just supply a music
cartridge with it's own independent clock source, you don't have
these problems, but instead expanded the conditions such a cartridge
can work with. Besides: a simple 3.58 MHz. oscillator might consist
of a cheap IC, a few resistors & capacitors, and a crystal. Build it
compact, and I couldn't think of any cartridge, where this wouldn't
fit into. And it won't cost anyone serious money either.
Conclusion:
----------------
Do this for yourself, for your computer(s) & your cartridges,
fine, but I would not support any attempt to set some standard for
these modifications. That would only be a source of problems for
years to come....
If you do, I suggest you make it switchable, such that in one state,
it works like non-modified (like with turbo-circuits: switch it off,
and it works like it wasn't there).
Putting a fixed frequency signal, and a variable CPU clock/bus speed
signal, side by side on a cartridge-connector is a good thing, but
for the MSX system, the chance to do so was lost with the definition
of the MSX standard, no way to re-do this.
Alwin Henseler ([EMAIL PROTECTED])
http://huizen.dds.nl/~alwinh/msx (MSX Tech Doc page)
http://www.twente.nl/~cce/index.htm (computerclub Enschede)
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