On Monday 22 January 2001 09:21, you wrote:
> Hi,
>
> for the last few day's I'm following the discussion about the extended
> ROM etc. I saw in a e-mail from Sean Young that he has 15 diffrent ROM
> types.
*SNIP*
>
> But I was wondering, how does my MSX handle all these ROM types ?
> because if I insert a r-type cart, my MSX run's it with no problems. So
> do all emulator's have a bug in the memory handeling ? Or does nobody
> know how a real MSX handles those ROMs ? Because if a emulator can
> detect it also, I only have to choose a ROM file, and not a type.
>
> Or am I complete wrong ?
Simply put, your MSX doesn 't know how to handle them!
All the memory handling is don inside the cartridge , by the chips on the PCB.
What the emulator progranmmers have to do in this case is not to emulate only
an MSX. The numbers of Sean Young are actually emulating parameters to
emulate the right cartridge-electronics.
As far as the (real or emulated) MSX are concerned they just ask the
cartridge: "Give me the byte on location X" or "write byt X to location Y".
once this command enters in the cartridge, it is the cartridge who (unvisible
for the MSX) starts to do all kind of memmory handling on its own. To emulate
that game you need to emulate a) an MSX b) a cartridge. The whole discussion
about the memmory handling here has been how to emulate the cartridge, and
not the MSX.
For end--users however this can be rather confusing ofcourse because they
just see the total picture and not the two (seperate) devices that are
emulated.
David Heremans
--
For info, see http://www.stack.nl/~wynke/MSX/listinfo.html
