As you might know we (the infamous xl2s entertainment ) are developing a game for the MSXdev'05 programming contest, named VKSD for now.

My question is: does anyone know an MSX where VDP, PSG or PPI isn't where it's supposed to be?
Or: when we don't use the BIOS and access the VDP, PSG and PPI directly using the I/O ports, will the jury be able to find an MSX on which our game will not run?

If you use the NEOS Version Up adapter, which is a cartridge to convert your MSX1 into an MSX2, the I/O ports of the VDP are not on the standard positions.... But this is totally not important, I guess, for your MSX1 game contest. Besides, I guess you can still get the base port from the BIOS, without using the BIOS really extensively (one read).

About vdp and or psg and or ppi location only some older msx1 has different addressing.... (svi 728 iirc) but iirc they are unused anyway because they are uncompatible.!

on used msx1, only is differences about keyboards but the primaries keys like RETURN, SPACE, direction KEYS, SHIFT , GRPH, CODE are all in the standard location. So for games it is all ok.

The bigger problem that bothered a lot to msx1 programmers is the location of the RAM memory, that some msx1 with 32 or 64kb RAM hasn't all the banks in the same slot/sslot.

And in the msx1 that has all RAM in one slot/sslot , the slot/sslot number varies according country or brandname.

sjoerd,

Using ld bc,0006h you can got the VDP data port in both B e C.

If you use inc C you will obtain the VDP command port (for addressing register and VRAM with out (c),register and status with in a,(c).

I use this method. In my country, Brazil, some guys use an cartridge adapter for MSX2 compatibility. But don't worry about that...

???????????????????

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Using ld bc,0006h you can got the VDP data port in both B e C.

??????????????

maybe is LD BC, (0006h)

/me sets mode flyguille -bifi

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maybe is LD BC, (0006h)

For sure...

Go on with the game, that wip design shot in your website looks very promising!

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About vdp and or psg and or ppi location only some older msx1 has different addressing.... (svi 728 iirc)

This is not true. You are propably messing up with SVI-318 /SVI-328 on them the VDP is in different location, but they are not MSX machines, so they don't have MSX-BIOS either.

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As you might know we (the infamous xl2s entertainment ) are developing a game for the MSXdev'05 programming contest, named VKSD for now. My question is: does anyone know an MSX where VDP, PSG or PPI isn't where it's supposed to be? Or: when we don't use the BIOS and access the VDP, PSG and PPI directly using the I/O ports, will the jury be able to find an MSX on which our game will not run?

My personal suggestion is : develop your game using 98h and 99h and
keep trace of all your I/O routines, labelling all the addreses of the port
numbers. This is easy if you keep all the I/O code in few routines.

In case want to gain compatibility with the standard (only in case)
you can always add a small init routing that substitute all the
port 98h and 99h with the ports in 0006h. If you use disk you can
run it once and modify the code on the disk.

If you run in a rom, the code to be modified must be in ram,
so you need to move there the I/O routines.

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Quote: About vdp and or psg and or ppi location only some older msx1 has different addressing.... (svi 728 iirc) This is not true. You are propably messing up with SVI-318 /SVI-328 on them the VDP is in different location, but they are not MSX machines, so they don't have MSX-BIOS either.

ok ok , by that reason i wrote IIRC (if i recall correct).

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/me sets mode flyguille -bifi

hey, leave me out of this willya!

MSX can do without BIOS, most stuff is pretty standard. however, before exiting BIOS mode, u might wanne save keep some vars 'n stuff. there are certain things that are stored in BIOS that are machine own.

f-kernel works pretty without BIOS, it's the perfect example.

ro - what's the status of F-Kernel now? Do you have the sources of the latest version? Can you implement a newer Wavedriver in it afterall? Do I need to kick Alex?

ro: Isn't F-Kernel for MSX2?

manuel: afaik PM got the Midas sources so he can do some updating himself.