VOGONS


First post, by megatron-uk

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Hi, just picked up a MT-32 (and hopefully a SC-55 soon) to go alongside my GUS MAX (1mb) & SB16 (CT2290) in my old DOS gaming machine.

I'm now looking for a proper MPU-401/AT, MPU-IPC or equivalent to hang the Roland synths from.

They seem to be a lot harder to find than the synths themselves.... does anyone have one spare that they would be willing to sell?

I'm in the UK, if that helps.

John

Reply 1 of 17, by Mau1wurf1977

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Habe you had any luck?

My tip is to look for MPU401AT clones. Midiman and Music Quest made such cards. They are 100% compatible, much easier to find and cheaper 😁

Reply 3 of 17, by Amigaz

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Not all Roland MPU401 clones are 100% Roland MPU401 compatible so you must choose model carefully (been there done thaT) or Roland MT32 music might sound wrong
Even the Roland Super MPU card isn't fully compatible

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Reply 4 of 17, by Mau1wurf1977

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Ah good to know!

Many years ago I used the MM401 from midiman, but I admit I only tried a few games. The ones I tried however worked fine...

I will be able to do more testing soon as I have a MM401 on it's way...

My website with reviews, demos, drivers, tutorials and more...
My YouTube channel

Reply 8 of 17, by keropi

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don't forget the possibility of the more common SCC-1 , as it also doubles as a fully functional Roland MPU 😁

🎵Link to buy a PCMIDI mpu
🎧Orpheus soundcard project
💻WTB Amstrad PC7486SLC-33 system

Reply 9 of 17, by Amigaz

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keropi wrote:

don't forget the possibility of the more common SCC-1 , as it also doubles as a fully functional Roland MPU 😁

Yep, and it's one zillion percent compatible 😀

Just make sure the midi cables are included

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Reply 10 of 17, by megatron-uk

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They're getting quite pricey though... I've been watching the prices of the SCC-1 on Ebay over the last couple of months... and they seem to be now quite expensive (comparatively, to external modules). Last one I saw (US based) finished well over £100. There's a buy-it-now one listed for £142.

Reply 12 of 17, by Mau1wurf1977

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megatron-uk wrote:

Did you find out if that MM-401 card works properly in intelligent mode? Do the Sierra games and Wing Commander work ok?

My Retro PC is out of order at the moment. I busted the CF card while playing with another CF-IDE adapter. So I got a new card underway, but can't test in the meantime.

but I am 100% sure it will work. Unless the card is faulty of course...

This is the product:

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Reply 13 of 17, by Mau1wurf1977

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Amigaz wrote:

Police Quest 3 is a good game to test if it you have a compatible MPU401 interface.

megatron-uk wrote:

Did you find out if that MM-401 card works properly in intelligent mode? Do the Sierra games and Wing Commander work ok?

My CF cards came today so I could finally install DOS 6.22 and get it all up and running.

Yes all the games work. Police Quest 3, Space Quest 3, Wing Commander are all working fine...

Reply 15 of 17, by Lord Nightmare

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If you have the means to, can you dump that rom from the MM-401? I'm curious if Midiman stole or licensed Roland's 6801 code from the real mpu-401 module/card, or wrote their own code from scratch.

LN

"When life gives you zombies... *CHA-CHIK* ...you make zombie-ade!"

Reply 16 of 17, by Lennart

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From what I've been able to find on the internet, it seems that the MM-401 doesn't use Roland's code. There's this old site which mentions: "The ROM instruction set on the card wasn't copied; it was designed from the ground up by some very capable and determined programming engineers". Furthermore, from the somewhat blurry pictures I've seen it appears that it's using an Intel microcontroller instead of a 6801 (could anyone confirm that?). And it's mentioned here on VOGONS that it's not completely 100% MPU-401 compatible, which could also be a clue that they wrote their own code instead of copying it. I agree that it would be nice to have a ROM dump though.

Hope this helps! 😀

Reply 17 of 17, by Lord Nightmare

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I suppose its possible! The first product Midiman (Who still exist, as M-Audio) made was called (unsurprisingly) the 'midiman' and did fsk-timing-recorded-to-a-cassette the same way the mpu-401 did; Making the MM-401 was sort of a logical next step (implementing the intelligent mode and other stuff of the mpu-401 plus the fsk stuff from the original midiman)

If anyone is wondering what the FSK (which btw means "Frequency Shift Keying" and describes a form of digital data stored on an audio cassette using different frequencies for 0s and 1s) stuff did, I believe it worked like such:
The midi data for one channel (possibly multiple channels depending on some details i'm not sure about) gets stored, with no timing information in a stack in the ram of say an appleII; The appleII runs in a tight loop direcly reading the cassette input and checking which tone is playing. when the tone being played pulses the other state, a byte is popped off the stack and sent via midi to a device.
Tl;dr: Its like a midi file where the timing data is stored as sync pulses on a cassette tape, but the actual midi data is stored as a raw binary block on the computer itself. (or so I understand; I could be wrong about this)

LN

"When life gives you zombies... *CHA-CHIK* ...you make zombie-ade!"