By testing emulators of Japanese computers, I've already discovered the (MS)X68000 (see another thread).

It's now the turn of the PC88, also a great success in Japan (only, as it was not released outside Japan)

It's not a very interesting computer for the BASIC or graphics possibilities, but what is very surprising is the Yamaha chip YM2608 (the chip for FM-PAC is YM2413)on the PC-8801FA model :

- stereo
- 6 channels FM + drumkit
- 3 channels SSG
- ADPCM (16khz) with 256kb memory for sampling

I think that we can compare that with the combination FM-PAC / Music Module on a MSX.

But I ask me why this Yamaha chip was not implemented on the last MSX models (MSX 2+ and MSX Turbo-R) ....

Has someone an explanation of this mystery ?

Please don't say me that it was impossible. The PC88 models have a 8bit standard chip Zilog Z80 4MHz or 8Mhz as main chip : you can compare that with the two speeds of the Z80 on some MSX 2+ models. So, what's the problem ?

The MSX-Audio was incorporated as an MSX sound chip very early. It took some time before the carts were on the market though. The FM-PAK was intended as a cheap sound-addon (hence the use of the OPLL (OPL-Lite) chip).

It lacks 9 extra FM chips to be really considered as a Music module/FMPAC combination though

I think it's not a real problem for any Yamaha FM chip to be used on a MSX computer, because most of them have huge similarities and only small differences.

But imagine, at the time.. no harddisks, no compact flash, expensive megaroms... why would anyone use 256KB samples that consumed a huge part of one DD-disk?

snout, you could be right there. Although I also think it has something to do with the costs. MSX was a low budget computer, if you ask me. We could also wonder why the V9990 was never implemented in the turboR, the technology was available, they even made a prototype mainboard for it....Still, they choosed the V9958. Why!? Same reason, because of the $$costs$$

The YM2608 (OPNA) is a member of a family of 3 FM chips. YM2608, YM2610 and YM2612. You can see how much a FM chip is different from another by looking at its code. OPN-chips are different from OPL (the type used for MSX-MUSIC, MSX-AUDIO and MoonSound) and OPM (The type used in Yamaha's SFG modules).

The difference between the families are e.g. different algorithms, so each family does have a very destinctive sound.

Ofcourse there is no problem connecting any of these chips to MSX. For instance, the NEOGEO uses a YM2612 driven by a Z80 CPU.

The reason not to have MSX implementations for all Yamaha chips is ofcourse, WHY!?! What is the point of a standard when everybody can have literally dozens of different FM extensions? Games would have to support all of the different extensions too, what a NIGHTMARE for composers!

IMO price or whatever has NOTHING to do with it. It's just impractical beyond reason!

Quote:

We could also wonder why the V9990 was never implemented in the turboR, the technology was available, they even made a prototype mainboard for it....

It was not a prototype but an EVALUATION board. Big difference!

You are right. Evaluation it was. sorry

That would be a nice board to have. Imagine, case open of your current turboR, old mainboard out and this evaluation board in. Close case, whoppa!

Seriously, the evaluation board does have the added functionality of the 640x400 and 640x480 modes. Although I'm pretty sure the Gfx9000 can be (and has been) modified to output those modes (needs a higher crystal clock), they are kind of useless being stuck at max. 16 colors...

So you need an OPLXX chip in the same range if you want to program it the same way like the chips we have now? Or is programming the MSX Audio chip a lot different than the OPLL in machine code?

Did Yamaha make any succesors to the OPL4?

I remember I asked Vortexion on #MSX a while ago if he could make a cartridge with the C64 MOS soundchip. He was busy with a prototype. Does anyone know if he succeeded? I still have some C64 machines lying around. I would be happy to donate those MOS chips for some protytype boards.

Only the OPL1/2/3 are similar from a programming point of view. The FM part in OPL4 is 100% identical to the OPL3, it just adds the wavetable channels.
OPLL is programmed differently, with different registers and also some limitations. Functionally it can be seen as a limited OPL2.

Other FM chips, like OPM (YM2151, used in the SFG modules) are different from both a programming and sounddesign point of view.

About the v9990 in the turboR... All video chips for MSX have been custom-made for the system. Well, at least the v9938 and v9958 were, the application manuals are quite clear about that. However, the v9990 is not v9958-compatible, which it would have been if it had been custom-made.

I heard a theory once that they were intending to fit 'the v9990' in the turboR, however that didn't work out for some reason. From there on Yamaha went their own way with the chip design and dumped all the legacy compatibility, creating the chip as it currently is.

~Grauw