The YM2413 Application Manual shows that it has separate output pins for 'melody' (MO, pin 14) and 'rhythm' (RO, pin 15) . It also gives a sketchy overview of how the OPLL needs to be hooked up to an amplifier. Figure IV-2 on page 20 shows that the RO and MO signals pass through a mixer which mixes the outputs and sends it to an mono LPF and Amp. So, in order to get a 'stereo-PAK', I guess all you need to do is *not* mix the signals and duplicate the LPF/AMP part...

Yes

Hi i'm working on a stereo fm-pac right now. This the mono edition that i build as a prototype:


Still work in progress, hope to add the stereo part next weekend.

LUPPIE

while you are at it a schematic of a build in thingy ? (to put in a 8250 or 8245?)


and ehmmm

where did you get the soundchip?

The schematics is for a cardridge, but i'm gonna try to hook it up in slot 3 in a NMS8250, so it ends up as a build in FM-Pac.
I have a contact in China that aranged 2 chips for me $ 20,- in total incl. shipping.

Where is the S-RAM part? A PAC need to have Static RAM ... Otherwise you will get a normal (generic) FM chip.

The RAM is used to hold the save games from the old titles. Like a backup cartridge.

Sure that only Panasonic (Matsushita) had the ORIGINAL FM-PAC with build in menu.

Indeed Yukio: fm-pac is often mistakenly used instead of msx-music. Btw. The stereo part, it's just seperating drum from the rest isn't it? I used to have it,but it's not really nice to have that seperation.

Yep, it does'nt have the SRAM and the stereo part is just a seperation from the RO & MO lines. Maybe I can try the spatial stereo, but that's an expensive mod.
My Goal is to just build MSX-Music into my NMS 8255

People reported that using a FM Stereo newer Television sets could output Spatial Stereo.

The MSX-Music is the Yamaha music chip, usually the with the cartridge ROM that the MSX-BASIC need. The PAC (Pana Amusement Cartridge) is the RAM memory for the save games ...

Some original games could save the game using the PAC and play using the MSX-Music from the FM-PAC cartridge from Panasonic.

I would least make it so that you still have a mixed output of RO and MO. The seperate drum ouput gets borring fast.

i argee with msd

I'm planning to use 1 stereo jack output. If a headphoneplug is inserted then MO + RO is seperated to left & right. If no plug is inserted then a mixed signal goes to the internal audio from the MSX that is connected to your TV

And how about mixing it with the psg?

What are you talking about? The FM Sound Stereo already is mixed with the PSG output, optionally the PSG output could be disabled. If a person already has Stereo output, it is possible to mix the two audio outputs for mono sounds ... Or in newer television there is a button to use Stereo or Mono sound, the DSP from the televisions could provide Spatial Sound too.

Mixed in side the msx, but trough the stereo jack you are making or is it?