That is indeed an AMAZING feature/breakthrough, kudos!!!!
But why is the SB still needed for this? Isn't the serial virtual mpu a separate device?

ps. still having plans to "overlay" on a real mpu to get rid of the annoying buffer overflow errors with the old mt-32?

SB's not required for serial output unless you want to run the Intelligent-mode titles that need interrupts (e.g. Gateway).
So for Monkey Island etc. you would only need to specify /output:com1.

Yep still planning to fix /DELAYSYSEX with Roland MPU before release.

ah, did not knew about interrupts, I get it now.... can't wait for the new version 😁

My Microchannel PC's and I thank you very much! This is awesome!

Unfortunately, no Roland MT-32 or compatible synthesizer has a serial mini-DIN style interface, only a MIDI DIN interface. I suppose if you had a SC-55mkII or other unit with a MIDI THRU, could you direct the MIDI data stream to an MT-32 via that route? I only have an SC-55ST like bjt, which does not implement a MIDI OUT or THRU.

I wonder if this simple adapter can be used: http://www.cinetix.de/interface/tiptrix/midi2rs.htm , any idea if this works?

keropi wrote:

I wonder if this simple adapter can be used: http://www.cinetix.de/interface/tiptrix/midi2rs.htm , any idea if this works? […]
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I wonder if this simple adapter can be used: http://www.cinetix.de/interface/tiptrix/midi2rs.htm , any idea if this works?

Ooh, that looks fancy. Wish I had soldering skills and those parts... That would be great for testing and trying out with my Roland MT-32.

I had no idea that with two resistors, you could turn the TTL-signaling based RS232 into a current loop based MIDI signal.

Unfortunately the baud rate won't be right without a more complicated adaptor. Another option is to change the crystal in an existing serial interface.

According to Wikipedia the MU-series will retransmit from RS232 to MIDI too.

Great Hierophant wrote:

I had no idea that with two resistors, you could turn the TTL-signaling based RS232 into a current loop based MIDI signal.

This is basically what Apple's MIDI adapter for the Macintosh/Apple IIgs does. The difference is the Zilog SCC chip driving the serial ports can do the 32kbps required for MIDI. I think the Amiga can get away with a simple adapter too.

bjt wrote:

Unfortunately the baud rate won't be right without a more complicated adaptor. Another option is to change the crystal in an existing serial interface.

According to Wikipedia the MU-series will retransmit from RS232 to MIDI too.

After reviewing what can be done for direct MIDI to serial, yeah a baud rate converter would have to be implemented somehow. And potentially a memory buffer. Unfortunately I don't have the experience to design something like that.

I might see if I can wire up serial to MIDI with some modded serial cards later (that is perfectly easy to do).

really great work, now my 386SX Laptop has MIDI Sound 😀
So i can get now a small Wavetable Module and wire it directly to Serialport.

Question:
Is it the case that games using Dos Extenders (e.g. DOS4GW) such as Doom & Duke 3D will not work with SoftMPU in Serial Midi mode?

Background:
So I got hold of a little industrial all-in-one pc board, and have been experimenting with setting it up as a Dos machine for classic gaming.
I followed the schematics and built a serial to mini-din 8 cable, as this was the only option I have for connecting this pc to my midi module, a Roland SC-55mk2.
The pc has a built in Soundblaster 16 compatible device at 220/7/1, and I initialize softmpu with the following command: softmpu /sb:220 /Irq:7 /mpu:330 /output:com1
It starts up ok and finds the devices. Tetsing with Megamid and games like Monkey Island work fine. Tetsing Doom I get no music, just sfx, and Duke 3D setup tells me it cannot find an MPU-401.

Some games I believe (could be wrong) use the physical MPU401 port on either the Sound Card itself or a Roland MPU401 or compatible device. Wish I had a MIDI to Serial adapter for my Retro PC, but alas, it has no serial port on it and neither does my Roland SC-55 (non mkII), but my Yamaha TG100 does though. If you installed NHL Hockey 95 on your computer with the Roland MT-32 as an option for the music, it'll say the same thing: no MPU401 card available.

Since the command you typed in is correct, honestly, I cannot figure out how to run Doom with the MIDI to Serial adapter.

After posting the question, I found some more threads here that basically confirm SoftMPU only works with real mode software. I actually have an MPU-401 intelligent clone isa card I could use, but don't have any way to connect it to this little PC I got without using a PC/104 ISA adapter (e.g. Acrosser AR-B1052), and i've only seen those for ridiculous money 🙁

You might be able to adapt the HardMPU design for the PC/104 form factor and build it up on a stackable breadboard or even a protoboard with a ribbon cable expansion.