Checking interest for DalSoRi version 2

I'm not sure if I understood your question correctly, sorry. But here's my best guess:

AFAIK, there are no OPL4 cartridges with the BIOS until now, be it built-in or any kind of add-on board. The only cartridges I know that have the MSX-Audio BIOS v1.3 are:

- Expanded Philips NMS-1205 and Toshiba HX-MU900 cartridges
- OPL3 cartridges made by MSXpro

The softwares that support the BIOS are:

- Nearly all Compile software
- All MSX-Music BASIC songs (and there are gazillions of them)
- Software that uses the MSX-Music via BIOS. Right now those are the games produced by ASCII and the FireHawk HDD.

Ok. Then the specs changed since the last time. Nothing against it. This approach has the advantage of being much faster, and the disadvantage of not allowing the YWR801 ROM to be updated anymore, and will require two ROMs (or flash chips) if the BIOS is present.

The approach with the BIOS has the disadvantage of taking more time on the 1st boot, but the advantage that the cartridge PCB would be much smaller and cheaper, as everything would be done with a single ROM (flash) chip.

In fact, with clever programming and that megarom, the BIOS can "stop itself". It's subtle, but take a look at that custom ASCII16 megarom again. In the boot, it would work like this:

1) The default of the configuration register is to boot with everything disabled, just like the original MSX-Audio BIOS

2) The BIOS then tries to detect if the I/O ports C0h and C4h are free, assigning its own OPL4 to the free I/O ports. This allows two cartridges to be easily connected together. It will even work fine with the old OPL4 cartridges that have fixed I/O ports. The original MSX-Audio BIOS also does this.

3) If A+B is pressed, the MSX-Audio BIOS will clear its own entries in the SLTATR table and copy a helper routine to the MSX RAM. This routine will select an empty page in the frame-1 of the MegaROM and return the processing to the MSX boot. Simple as that.

I don't think you could even find a YSS225, but also I think you don't have to. The digital outputs (FM, WAVE and MIX)of the opl4 are quite standard. You can probably connect some other effect processor to it. I don't know if there is an effect processor chip with more than one input that also replaces the YAC513. You wouldn't want to mix the outputs together again in the analogue domain. Also the opl4 only has one bit per channel to select the output. There is no volume control per ouput. But It would be easy to implement.

@sd_snatcher

I don't know AM29F032 is still available, even if available, it's price seems more than 30USD in Korea.
YRW + small flash combination is cheaper solution.

Then wasn't MSX-AUDIO v1.3 tested on the pure (without any other sound cartridge) OPL4 cartridge?

UtSource seems to have these two:

• AMD AM29F032 for $16.67 (10 pcs)
• ST M29F032D for $13.33 (10 pcs)

It was tested with the OPL3 cartridge. Since there's no WaveTable support yet, there isn't any other significant difference between the OPL4 and the OPL3. Unfortunately, nobody has built any OPL4 cartridge with the BIOS yet.

A brand new account with only 4 posts, some technical knowledge and some quite strong words, like "poison", "hack", and "pet project". Is it only me that a smell a puppet here? If this isn't the case I hope it wasn't created to start yet another flame war.

If you dislike the BIOS, there's nothing I'll say that will change your mind. There's nothing to win from that. But when you try abort an innovation, you're trying to make people not have something that they could.

And you know that there are already plenty of nearly functionally identical Moonsound clones out there just with the limited specs you desire. Just buy one that pleases you most. A bonus tip: If you don't like the YRW801, it's very easy to remove it from a Tecnobytes Shockwave since the chip is DIP.

But please, you don't need to create a puppet profile to defame other people's projects. I really hope you aren't some guy I heard that likes to spawn in these forums from time to time just for the pleasure of bashing other people's ideas.

Do you have any references for this information? Because the source I checked is called "MSX Turbo-R Datapack", and AFAICR doesn't mention anything like that. What it mentions with very clear words is that user programs aren't allowed to do direct hardware I/O. And this is clearly stated in the MSX-Music chapter too.

The reason, as you know, is also clearly stated in the MSX Technical Handbook: the maker was allowed make hardware changes and change the BIOS to hide the differences. Even the keyboard interface is mentioned that could be completely different, like using a wireless chip to do the job.

Along these lines, I believe that the MSX-Audio BIOS v1.3 is no hack. It implements the FMBIOS calls inside the MSX-Audio BIOS. Since the MSX-Music BIOS was itself just a subset of the MSX-Audio v1.0 BIOS, my think that this convergent evolution is perfectly acceptable. Even better, to me it's like merging a fork back to the original source. ;) . But that's only my point of view. You're not required to agree.

Option-3 might be your best option, but certainly is not everyone's best option. And I wouldn't try to impose: it's JunSoft's project, and he's probably investing his scarce spare time for that. I'm just trying my best to contribute with some ideas, tips and options (as I do for many other projects), but its his choice to decide what's best for the design.