OPNA for MSX - Anyone working on one to market & interest?

بواسطة Pencioner

Scribe (1612)

11-03-2018, 18:05

If there's someone to produce OPNx (OPN, OPNA, OPNB, OPN2) cartridge count me in, i will buy one.

بواسطة Wierzbowsky

Guardian (3651)

11-03-2018, 18:59

I may be also interested in the DIY kit or just the plain board. If the price is reasonable, of course. As far as I know from Grauw there were 2 guys involved in OPNA board development - Leonard Oliveira and Fábio Belavenuto:

https://twitter.com/leo__oliveira
https://twitter.com/fbelavenuto

بواسطة Giangiacomo Zaffini 2

Champion (300)

11-03-2018, 19:54

I'm intetested too. I think we are at a stage that every cartridge for MSX should have as much RAM banks as possible. IMHO.

بواسطة syn

Prophet (2135)

11-03-2018, 21:02

Giangiacomo Zaffini 2 wrote:

I'm intetested too. I think we are at a stage that every cartridge for MSX should have as much RAM banks as possible. IMHO.

you mean ram banks as in memory mapper? That isnt practical since we need to put it in slot expander, so we can play music from all kinds of soundchips, instead of needing to swap every other song

بواسطة Grauw

Ascended (10821)

11-03-2018, 21:13

@Meits OPNA can not emulate MSX-MUSIC, @msd nor can OPL4 emulate OPNA. The N and L series are too different. The Yamaha SFG (OPM) can partially emulate OPNA, due to similar operators, but the ADPCM and PCM drums are missing.

@syn RAM as in sample RAM. The OPNA can have 256K for ADPCM, just like MSX-AUDIO. Also, lately I’m of the opinion that it’s better to create MSX trackers for PC than for MSX, better for development speed and usability. With playback on MSX via MIDI.

I think an OPNA cartridge should be easy to create; address decoding logic, OPNA, DAC, RAM, done.

And I would surely buy one. The more sound chips I have for MSX, the happier I am .

بواسطة syn

Prophet (2135)

12-03-2018, 01:06

Grauw wrote:

@syn RAM as in sample RAM. The OPNA can have 256K for ADPCM, just like MSX-AUDIO. Also, lately I’m of the opinion that it’s better to create MSX trackers for PC than for MSX, better for development speed and usability. With playback on MSX via MIDI.

~~yeah if the emulation is 100% accurate, PC works as well. I've only used MB1.4, triltrotracker, MS2 in emulator anyway since i prefer working on PC.~~
*edit* i misread your post, you were talking about midi to real msx

Quote:

And I would surely buy one. The more sound chips I have for MSX, the happier I am .

this (if its not too expensive at least)

بواسطة Avkooi

Expert (101)

11-03-2018, 22:15

I would buy one if the price is in the same league as the other ones (DalSoRi, GR8NET etc.) Lots of great vgm's for YM2608. Always love to hear the tracks on real hardware!

بواسطة Pencioner

Scribe (1612)

12-03-2018, 00:17

Grauw wrote:

The Yamaha SFG (OPM) can partially emulate OPNA, due to similar operators, but the ADPCM and PCM drums are missing.

@syn RAM as in sample RAM. The OPNA can have 256K for ADPCM, just like MSX-AUDIO.

Hmmm... what if MSX-AUDIO and SFG inserted into the same MSX - would it be possible to play OPNA with OPM + PSG (this part is already in vgmplay for MSX) + ADPCM from MSX-AUDIO or GR8NET? Do they have too much differences in PCM data format?

بواسطة syn

Prophet (2135)

12-03-2018, 01:04

Opna has 6 channel adpcm drums from a ROM + one channel additional adpcm https://en.m.wikipedia.org/wiki/Yamaha_YM2608
Msx-audio is 1 channel adpcm. And i havent even looked at bitrate differences yet (if there are any)

So you would probably need an opl4 (i doubt that you can mix down 7 channels to 1 msx-audio adpcm channel on a z80) + opm +psg for a full "emulation". Not sure if that would be worth it to code, if a seperate OPNA cartridge is available ;)

بواسطة Pencioner

Scribe (1612)

12-03-2018, 01:08

syn wrote:

Not sure if that would be worth it to code, if a seperate OPNA cartridge is available

I'd definitely go for a cartridge of course

PS Just tried to find it on ebay and wondering if those 3-4 EUR chips from Hong-Kong and China are fake ones or is it really cheap IC ? The OPL4 IC was much more expensive...