This is what in a way gets my goat about the Megaflashrom cart - you are paying more for the "all in one" convenience, except that it lacks FM pak sound so doesn't quite cover all bases, so you still need to add a seperate FM pak solution.
I already see you ranting about this quite frequently. It is not good. If I would be you I would be patching recovery ROM and FM-ROM in a way they work on same slot and sending that patch back to Manuel. -> It is rarely working solution to rant in a public forum, better is to offer help for the people who are working with these issues.
Ranting, quite frequently? I don't think so, also I have already stated I'm completely new to this format so I have no idea of the pitfalls of making these things working together. I'm only stating what I and I suspect others would ideally like to see as a solution, perhaps this is coming across as being pushy I don't know but it's not overly serious. I have several different retro machines and just want to get the best out of them using new hardware solutions, if anything I'm seeing that the MSX hardware compatibility is a bit more fragmented than other systems and this has surprised me a little.
Ranting, quite frequently? I don't think so, also I have already stated I'm completely new to this format so I have no idea of the pitfalls of making these things working together. I'm only stating what I and I suspect others would ideally like to see as a solution, perhaps this is coming across as being pushy I don't know but it's not overly serious. I have several different retro machines and just want to get the best out of them using new hardware solutions, if anything I'm seeing that the MSX hardware compatibility is a bit more fragmented than other systems and this has surprised me a little.
Sorry, I think I should take that back... I think I woke up with a wrong foot or something. It might be that I also mixed you up with some other, who wrote about this same idea not very long ago in a bit negative tone.
It is not a bad idea at all, but please note that it comes up with many things to consider:
1) Although this is not extremely hard, it requires a bit more than just smashing OPLL to the soup. Unlike SCC this chip requires external opamp and more knowledge of analog stuff.
2) I think it is already pretty crowded in the cartridge and we are talking about multiple chips & analog signals here... Sure this can be always solved by increasing the cartridge size up a notch. Cartridge case size is probably the biggest issue... One proto is easy to make with 3D printing, but if you need many, it becomes very impractical very fast. Making a mold on the other hand is so ridiculously expensive that you would need to sell 50 000 pcs to keep the costs reasonable. I think it needed quite a bit collaboration between hobbyists to get the current cartridge cases produced without costing an arm and leg.
3) The main customer audience are people who have had MSX for years or decades. They most likely already have internal or external MSX-Music.
4) How much people are willing to pay extra for integrating this feature as well? Bigger PCB + Bigger case + more electronics = more work, bigger price.
I don't say that this project has to fall to every mentioned tar pit, but it does involve some more things than quickly meets the eye.
Welcome !!