We tried Win98SE, WinME and FreeDOS (with softMPU too).
AMD K6-2 350MHz+192MB RAM, nVidia Vanta 16MB. Pentium II Celeron 400MHz 256MB RAM and S3 Savage4 32MB.
Note that these are not my DOSgaming computers, that one does not turn on anymore, only fans spin...

We both have this cable, can it be wrongly wired? https://www.gearslutz.com/board/attachments/l … 8e3033e0ca1.jpg

We were unable to push out a single note on the gameport cable. Only USB and physical MPU-401 worked... We tried about 4 soundcards. PnP and non PnP SB16, AWE64, Vibra16.

[off]Currently I am busy with my university studies. I ordered USB MIDI, which I can use with the SC-55 on my current desktop with DosBOX. Will retry this gameport stuff later when I get some time. I don't see any chance to get an MPU-401 anyway. If you have advice feel free to share, it will be appreciated. I don't say I will test it quickly, but will consider it for sure.[/off]

I guess it's time to check whether that MIDI gameport cable actually is soldered correctly. Is it the one that's sold by that one Ebay seller who always has many of them?

(I actually bought one of those cables but didn't try it yet, so if yours is from the same source I should maybe check my own cable...)

No, this is about 20 years old. I bought it second hand locally, but the owner never used it. I don't like the design to be honest, the cable is in the way on ISA cards, it is only okay with PCI ones...

Merry Christmas guys! I am back with a status report.

Long story short, it was the cable...

Here is a flickr album: https://www.flickr.com/photos/quailland/album … 157688674909422

I bought another cable, which looks like this:

Notice the two transistors which turn the UART MIDI out of the computer to a standard current based signal.

The original cable which I suffered with looks like this:

It only has the optocoupler for input, but on the output nothing at all, just resistors. No wonder it did not work.

I will try to fix this later with a NAND gate probably.

A passive output like that will work fine if the sound card has a low impedance 5V MIDI pin. A transistor buffered output is certainly better, but the second converter should work in most circumstances.

Well, it certainly doesn't work with Roland SC-55 or MT-32. No matter what soundcard you use. (we have two of this bad cable)

Sounds like somebody screwed up, then. Improper design or QC glitch.