The standard in MIDI interface was the MPU-401, first introduced as a standalone hardware by Roland in 1984, and then integrated into PC soundcards.
The MPU-401 had 2 modes:
* In UART mode, it acted as any other MIDI interface, passing MIDI data between the computer and external MIDI devices
* In intelligent mode, the PC offloaded the MIDI playback task to the interface, freeing the PC to do other tasks while the music was playing
== Schematic ==