Years later, I tried the game on MAME, but felt that something about the sound was off.
If you haven't tried lately, you may want to try again later this month (or now, if you can compile your own). OPN emulation improvements went into MAME just a few weeks ago and will be released with MAME 0.230. We're hoping that MAME 0.230 will have OPL family improvements as well, but that might get pushed back until MAME 0.231, we'll see!
I'm sure it has improved, since it has been years since I last tried it. I think the release was like from 2011 or 2012.
OPN/OPM family generally sound a lot different than OPL. I can't think of any soundtrack for one that might be mistaken as coming from the other. Maybe the OPL3 4-op mode would sound similar but it's hardly used and still lacks detune and some of the algorithms. I remember in the '90s there was an early version of Genecyst which used OPL3 to emulate the YM2612. It wasn't accurate but it was fun to try out various games just to see what the mutated music would sound like.
OPN/OPM family generally sound a lot different than OPL. I can't think of any soundtrack for one that might be mistaken as coming from the other. Maybe the OPL3 4-op mode would sound similar but it's hardly used and still lacks detune and some of the algorithms. I remember in the '90s there was an early version of Genecyst which used OPL3 to emulate the YM2612. It wasn't accurate but it was fun to try out various games just to see what the mutated music would sound like.
I always found the OPM/OPN music to sound better than the OPL family most of the time. I have never liked the OPL2 and only respect the OPL3 more for what it can do. I just can't help but wonder how challenging it would be to put an OPN/OPM chip on an 8-bit ISA card. It probably wouldn't be worlds different or difficult to make as compared to an Adlib card. I love FM synth, but only when it's done correctly (i.e. not sounding like farts).
I just checked on it, and the OPNA does support single-channel 8-bit ADPCM sound between 2 and 16khz. So theoretically, it should be possible to playback some audio samples on the chip. Though it would be better to introduce an onboard DAC with less limitations.
If you don't plan to play more than one sound at a time it can work, but for more things get difficult since the chip is really only meant to play stuff from its RAM which is assumed to be non-changing / infrequently updated, i.e for short SFX and drum sounds etc.
The RAM is pretty slow to update but you do get double buffer feature if you really wanted. I'm not sure how much overhead encoding samples to the required format will have if there's plan to software mix multiple channel together (which one will have to do with other PC specific things anyway if more than one channel is necessary).
If you don't plan to play more than one sound at a time it can work, but for more things get difficult since the chip is really only meant to play stuff from its RAM which is assumed to be non-changing / infrequently updated, i.e for short SFX and drum sounds etc.
The RAM is pretty slow to update but you do get double buffer feature if you really wanted. I'm not sure how much overhead encoding samples to the required format will have if there's plan to software mix multiple channel together (which one will have to do with other PC specific things anyway if more than one channel is necessary).
It sounds like an external DAC would be better in this scenario.
Just found a translated datasheet: http://nemesis.hacking-cult.org/MegaDrive/Doc … 0Translated.PDF. I'll need to read through it before I can figure out what a board design may look like. Do you have any recommendations for a separate DAC? Preferably, it should be 8-bit and support several voices/channels.
Edit: It appears that the YM3016 is often used as a companion DAC.
The FM chip itself needs a DAC for some of its analog sound output, which is one of the YM30xx series parts. AY part in the OPN/A/B chips has analog output from the chip and FM + ADPCM side is digital and needs a dedicated Yamaha made DAC for it. You then mix the analog sources together into final output.
For PCM sample streams you need a dedicated mechanism, cheapest and simplest being a Covox clone setup that captures LPT writes off the ISA bus (which is what I do on my Yamaha YMF71x card).
The FM chip itself needs a DAC for some of its analog sound output, which is one of the YM30xx series parts. AY part in the OPN/A/B chips has analog output from the chip and FM + ADPCM side is digital and needs a dedicated Yamaha made DAC for it. You then mix the analog sources together into final output.
For PCM sample streams you need a dedicated mechanism, cheapest and simplest being a Covox clone setup that captures LPT writes off the ISA bus (which is what I do on my Yamaha YMF71x card).
I like the covox idea. It would probably be the most era-appropriate too.
The Covox DAC is appears to only be mono, so two would be required to have it in stereo. This is probably fine though, since it would take almost no space up on the card.
Interfacing OPN to the ISA bus is quite simple, most of the circuitry on the card would be for the audio. It would be pretty similar to an Adlib card, even using the same Y3012 DAC, the only difference is the need to mix in the SSG sound. OPNA would be more complicated since it is meant to have external memory.
I'm not sure how the discussion changed to PCM. Aren't there enough existing sound cards for that? But if you wanted to play PCM from an OPNx for some reason there are software hacks to do it, or you could use those dual 8-bit I/O ports that they have. That would mean that the DAC data register is hidden in the register file instead of being at a separate I/O address which is not ideal, but hey it was good enough for SEGA...
Hi again. Sorry for my little necro, but I've found some interesting trivia.
The PC-98 (C-Bus) version of Creative's SB16 included the OPL3, but had an optional socket for an OPN!
This was for backwards compatibility, because the OPN was the PC-98's equivalent to our AdLib.
In a platform sense, I mean. We started with OPL2 rather than OPL (OPL1).
Here's what a Japanese website says (machine translation) :
Manufactured in February 1994. Sound Blaster 16 was very popular in the overseas IBM PC compatible market and was essential for both DOS and Windows games. However, in the PC98 market in Japan, there was the NEC PC-9801-86, which had expanded functionality while ensuring compatibility with the NEC genuine sound board (PC-9801-26K), which was already becoming popular. This was a minor presence.
In fact, very few PC98 version MS-DOS compatible software/games are compatible with this sound board, and it is of little use under DOS. However, limited to Windows 3.1 and 95, the PCM recording and playback function was surprisingly more stable than the 86 sound source.
If you install the optional Advanced Signal Processor (model number: SB-ADSP/J), you can use ADPCM hardware encoding when recording. In addition, by installing YM2203 and YM3014 (model number: SB-YM/J), you will be able to use the sound function compatible with PC-9801-26K, increasing its use for PC98 games. The MIDI sound source daughter board WaveBlaster can also be installed. [..]
"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel
If anyone really wants to get into PC-98 sound boards, this crazy device lets you connect two boards via USB to modern windows. The Neko Project II emulator has native support for it as well. https://www.kadenken.com/view/item/000000000506
If anyone does decide to make an OPN based card, the YM2610B (OPNB-B), is the ideal chip, but sadly it's really hard to find legit sellers now, I'd say 90% of listed chips are fake.
Thanks! That sounds interesting! 😎
So there's a real chance to implement things in a manner that's worth it.
I wonder, would it be possible to create such a card in a way that's compatible with the PMD driver used on PC-98 ?
Or maybe is it a bit naive too assume that PMD musical driver will work as a drop-in replacement for PMDIBM (used by some DOS/V ports) ?
Or are there differences in the music formats being used on both versions ?
I'm just wondering, I vaguely remember informing myself about such things years ago but haven't been into the technical details for a while.🤷♂️
I merely know that certain DOS text-mode applications (basic ASCII) can run fine on both NEC and IBM based platforms without modification.
Unless invalid assumptions about i/o memory locations for certain devices are being made.
I also vaguely remember that some CD-ROM releases of certain titles had both minimum requirements for PC-98 and
DOS/V being mentioned.
So I assume these games must have been using drivers for graphics/sound to work on both platforms. Or use two separate executables.
Anyway, my memory is a bit sketchy here.
It's been a few years already and I really need to refresh my memories. 🙁
Could also well be that those games were from PC-9821 era already, which also had MS Windows titles at hand.
Edit: Just noticed I've mentioned PMD on first page already. My memory really leaves a bit to be desired. Oh my. 🙁
"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel
There's a level of compatibility when the programs only use DOS API calls to do stuff, but when they start using BIOS calls or access hardware directly things break down. IO map and BIOS are completely different on these machines.
When used properly the OPL3 can sound very very good indeed. Old MS-DOS titles mostly just set the parameters and then triggered notes with a MIDI file or something equivalent. It was easier to make a GM soundtrack and then use the OPL as an MIDI tone generator as an afterthought than to create a proper FM version of the soundtrack.
If anyone does decide to make an OPN based card, the YM2610B (OPNB-B), is the ideal chip, but sadly it's really hard to find legit sellers now, I'd say 90% of listed chips are fake.
Imagine a world where a YM2203 based sound card managed to be first in the MSDOS PC gaming market and managed to get wide support, we might have eventually ended up with YM2610B sound cards and GM on MS-DOS games might never have taken off. An OPN board could have been cheaper than either the Game Blaster or the Adlib while still having adequate capability (three PSG and three 4op FM channels)
I just checked on it, and the OPNA does support single-channel 8-bit ADPCM sound between 2 and 16khz. So theoretically, it should be possible to playback some audio samples on the chip. Though it would be better to introduce an onboard DAC with less limitations.
The OPNB has:
Four 4 operator FM channels (or 6 channels if YM2610B)
Three PSG square wave/noise channels (AY-8910 basically)
Six fixed frequency 12-bit 18.5kh ADPCM channels
One 16-bit ADPCM channel with playback frequency from 2~55.5hkz
ADPCM is compressed as 4 bits per sample and decompressed during playback.
So this thing would have made one hell of a sound card back in the day, especially the "b" version with 2 extra FM channels. Japanese PCs actually did go with the OPN family instead of OPL but I don't think they ever had an OPNB card. It's most famous use was in the SNK Neo Geo and here's what it sounded like there: https://www.youtube.com/watch?v=deb4BGycmF8
