Snover wrote:

I know that Vlad was/is working on some software MT-32 emulation. What's the status on that, Vlad? Also, I'm thinking it would be a step ahead if you could come up (at least in the meanwhile) with, in VDMSound, a way to map a game's samples to a SoundFont for at least sort-of working pseudo-emulation.

Status is "paused" (I branched into a related side-project to build a digital probe to get the digital output from the MT-32). The logic behind L/A synthesis is simple, but accurate implementation (i.e. getting the numbers right) is tough without the right tools. 😀

Any electrical-engineer around who can lend a hand with the design? 😉 FPGA/PLD based, for the parallel port using ECP (for n*100kHz/MHz sampling rates).

V.

As a matter-of-fact, I've got a friend that's an electronics engineer. (Well, a sound engineer, but he's damn good with electronics, too.) I'll get in touch with him.

Will this emulator use the sound samples from an MT-32 MIDI bank?

dnewhous wrote:

Will this emulator use the sound samples from an MT-32 MIDI bank?

Yes, but it's not that simple. The MT-32 has 128 PCM samples, but those samples are not necessarily what you hear (they can be mixed together as well as with generated square of sawtooth waves, filtered, LFO'ed, etc. to generate richer sound).

V.

Still no response from my buddy. I suppose he's on vacation or something, what with it being the end of July and all.

Interesting program for Vlad:
http://home.modemss.brisnet.org.au/~mlevoi/vbsyx.html

Enjoy.

Would I be causing trouble by posting a link from this message over at Sierra-Quest? 😉

http://www.sierra-quest.com/cgi-bin/ikonboard … forum=3&topic=3

Wow, great information, Nicht!

http://www.sierra-quest.com/mt32/MIDI_Implementation.txt and http://www.sierra-quest.com/mt32/MT-32_Patch_Banks.txt I don't think I saw before, but I know I posted the MT-32 manual before.

Thanks, guys (Stiletto, Nicht, Snover), but I already have that info (system exclusive format + checksum calculation, MT-32 manual + MIDI impl., as well as the LAPC-1 MIDI impl. and D-50 basic and advanced manuals). 😀 That's why I say I have almost everything I need to get started (other than the actual digital recordings of the beast in action, i.e. I know all the theory by know, but I need the empirical "touch" too 😁 ).

Cheers,
V.

You *have* an MT-32, correct?

Snover wrote:

You *have* an MT-32, correct?

I have a LAPC-1. Same thing. Almost.
V.

Go make that damn emulator already then 😁

I'll second that motion.
Still no word from my buddy. I'm about ready to give up on him (till September, when I can bitch at him for not writing back 😉)

Did the MT-32 have digital effects like reverb? If so how do you intend to emulate that?

Somehow get the algorithm off the LAPC-I?

Write your own? Hah! Unless you're a DSP god that will take a lifetime.

Use EAX to imitate as close as possible? (Thus using the resources available on modern sound cards.)

Do most modern sound cards (not just Creative Labs') have EAX?

DirectX has a reverb DSP, so if Vlad uses DirectX libraries, there's no problem.

Oh, I got a response from my buddy today:

Colin, I have been very busy. I am sorry that I have not been able to respond to your e-mail.

I would like to help you with the emulator project, but I don't know if I would have the time to commit to it. It has been a while since I have done those, so I would need some review time.

It sounds like he MAY or MAY NOT be able to do it. I asked him if he knew anyone with more extensive MT-32/LAPC-1 knowledge.

Snover wrote:

Do most modern sound cards (not just Creative Labs') have EAX?

As far as I know, no. EAX is a Creative Labs-only thing. However, other sound cards may have similar environmental effects of their own devising.

Stiletto wrote:

As far as I know, no. EAX is a Creative Labs-only thing. However, other sound cards may have similar environmental effects of their own devising.

If EAX is Soundblaster specific, how is it my sound card (not Soundblaster) adds reverb when I activate the EAX switch in a game (Baldur's Gate I and II)?

My understanding is that EAX is just a specification for how to store and send reverb parameters in a game. Any card from Turtle Beach, Creative Labs, or Philips will be able to read and use the reverb parameters.

They all have different reverb engines for what they do with the information. Sounblaster's is the best, though the competition is getting better at it.

If they were using something besides EAX you would need to have separate switches in the game for each sound card.

Everyone who uses EAX has to pay licensing fees to Creative Labs to be allowed to read EAX.

The reason Aureal got sued is that their cards implemented EAX without paying Creative Labs for reading the information.

Well, that sucks. I vowed I'd never get another Creative Labs sound card after this Audigy fiasco, but if they're the only ones with EAX, I dunno... I might have to.

dnewhous wrote:

Did the MT-32 have digital effects like reverb? If so how do you intend to emulate that? […]
Show full quote

Did the MT-32 have digital effects like reverb? If so how do you intend to emulate that?

Somehow get the algorithm off the LAPC-I?

Write your own? Hah! Unless you're a DSP god that will take a lifetime.

Use EAX to imitate as close as possible? (Thus using the resources available on modern sound cards.)

Of course it did have reverb. 😁 And no, you don't have to be a DSP god to reverse-engineer the MT-32 reverb(s) as long as it's linear and as long as you have a digital way of recording. The MT-32/LAPC-1 reverb transform is then only two (D)FFT's and a string-division away.

V.