MiSTer FPGA Forum

I have trouble getting external MIDI devices to work constantly with the core. I tried a Casio Keyboard and a SC88 ST Module. I connect them with a cheap USB MIDI Adapter. The devices work flawless with the Atari ST core so I don't think the adapter is to blame here.

The MIDI works but it usually takes several attempts where I have to reset the MIDI port until everything works. Before it works only random notes are played through the external MIDI device. The adapter is sending data when this happens as the transfer LED on the adapter flashes. Has anyone an idea or similar experiences?

I strongly suspect you answered your own question when you said "cheap USB MIDI Adapter". Not all USB MIDI adapters are created equal. I recommend a Roland UM One MK II.

You can also try setting DELAYSYSEX=FALSE in your MidiLink.ini file. This may help.

Editing the MidiLink.ini file didn't help, so I guess it is the adapter even if I don't understand it, it works without any problems with the ST core.

Chris23235 wrote: ↑Wed Oct 21, 2020 6:47 pm The MIDI works but it usually takes several attempts where I have to reset the MIDI port until everything works. Before it works only random notes are played through the external MIDI device. The adapter is sending data when this happens as the transfer LED on the adapter flashes. Has anyone an idea or similar experiences?

I have identified a bug where the UART can potentially be set to the wrong BAUD rate for the ao486 core..

You can try this work-around until I submit a better fix:

• 1. Unplug USB MIDI adapter
  2. Set OSD: MIDI/Local/MUNT or MIDI/Local/FSynth <-- this will cause 31250 BPS to be used by core
  3. OSD: Save
  4. Replug in USB MIDI adapter
  5. OSD: Reset UART connection <-- causes MidiLink to be reloaded

The problem was indeed the wrong BAUD rate for the MIDI adapter, but it seems the wrong rate was set by default. My MIDI link file set the BAUD rate for ao486 to 38400 and according to the github page this is default for this core. I changed it in the OSD and it seems it only worked now and then to change and reset the adapter and it also seems it was never written to the MIDIlink.ini. When I manually changed the rate in the ini to 31250 everything worked.

Thanks to everyone for the help. I love the sound of the SC88 it is a wonderful experience to play Doom this way

Agreed. I got an SC-55 for this reason. Lovin it

Chris23235 wrote: ↑Wed Oct 21, 2020 10:09 pm The problem was indeed the wrong BAUD rate for the MIDI adapter, but it seems the wrong rate was set by default. My MIDI link file set the BAUD rate for ao486 to 38400 and according to the github page this is default for this core. I changed it in the OSD and it seems it only worked now and then to change and reset the adapter and it also seems it was never written to the MIDIlink.ini. When I manually changed the rate in the ini to 31250 everything worked.

SoftMPU uses 38400 but the new semi- "intelligent Mode" MPU-401 changed to 31250.

The "Save" is for the ao486 OSD config. It does not alter the MidiLink.INI.

"Reset" simply calls the "/sbin/uartmode" script which reloads the Console, PPP or Midilink daemons - causing default BAUD rates to be restored.

I think you were setting the BPS to 31250 then immediately resetting it back to 38400 (from the INI) with "Reset"...

Thanks for the explanation.I didn't knew that there was a difference in the OSD options and the MidiLink.ini. As I don't use the SoftMPU it shouldn't be a problem to change the setting in die ini.