MPU-401

MPU -401 (MIDI Processing Unit MIDI Processing Unit) was an important standard for MIDI interfaces for PCs, originally presented by the Roland Corporation, which also participated in the definition of the MIDI standard.

The original MPU -401 was an external breakout box which had connectors for MIDI IN / MIDI OUT / MIDI THRU / TAPE IN / TAPE OUT / MIDI SYNC and to be purchased separately along with a specific for each computer system Erweiterungskarte-/kassette (so-called " MPU -401 interface Kits" ) was operated. For this combination, the following interface cards are available:

  • MIF - APL: For the Apple II
  • MIF - C64: For the Commodore 64
  • MIF FM7: For Fujitsu FM7.
  • MIF -IPC: For the IBM-PC/IBM XT and compatibles.
  • MIF -IPC -A: For the IBM AT. The original MIF -IPC did not work reliably with faster processors.
  • MIF MSX. For the MSX
  • MIF - PC8: For the NEC PC -88 series.
  • MIF - PC98: For the NEC PC -98 series.
  • MIF X1: For the Sharp X1.

Later Roland shifted most of the electronics from the breakout box to the interface card itself, thereby reducing the size of the breakout box decreased:

  • MPU -IPC: For the IBM-PC/IBM XT / IBM AT and compatibles (8-bit ISA).
  • MPU -IPC -T: For the IBM-PC/IBM XT / IBM AT and compatibles (8-bit ISA). The MIDI SYNC pin has been removed, and the I / O address and the IRQ line for the first time could be adjusted by jumpers.
  • MPU IMC. For the IBM PS / 2 and Micro Channel Architecture bus, its
  • LAPC- I: For the IBM PC and compatibles. Contains the Roland CM- 32L sound source. The breakout box for this card (MCB -1) was sold separately.
  • RAP 10: For the IBM AT and compatible (16-bit ISA). Includes a General MIDI compatible sound source. Only for UART mode. The breakout box for this card (MCB -10) sold separately.
  • SCP -55: For IBM -compatible laptops (PCMCIA). Contains the Roland SC -55 sound source. The breakout box for this card (MCB -3) was sold separately.

Finally, we decided against the breakout box and gave all the connections on the back of the plug-in card:

  • MPU-401/AT: For IBM AT and compatibles. Provides a connection for wavetable daughterboard.
  • MPU - PC98: For the NEC PC -98.
  • MPU PC98II: For the NEC PC -98.
  • SCC- 1: For the IBM PC and compatibles. Contains the Roland SC -55 sound source.

The MPU -401 can operate in two modes: normal and UART. In normal mode, the host system things like an 8 -track sequencer, metronome or the issue of synchronization pulses are available; Because of these features of the normal mode is also often referred to as a "smart " mode, in contrast to the UART mode, which reduces the MPU 401 on a forward - and outbound MIDI data bytes.

The fact that the computers were becoming more powerful, the possibilities of the "intelligent mode " has become superfluous, as it was more efficient to provide them with appropriate software routines. Thus, the UART mode became dominant, which went so far that the most compatible card does not support (for example, Sound Blaster 16) the " smart mode ".

While the Linux kernel until today (2012 ) contains a driver for MPU - 401 provides the Microsoft Windows operating system from Windows Vista no longer supports MPU - 401.

  • MIDI
IBM Personal Computer Jumper (computing) Host (network) Music sequencer
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