MIDI Interface Cards for the IBM PC

What is a MIDI Interface?

A MIDI interface is the hardware which allows a computer to talk to MIDI instruments. It sits between the computer and a MIDI device such as a synthesizer or a sound module. Some MIDI interfaces are internal, often in the form of an expansion card or board, external in its own box, or a mixture of two. Some computers like the Atari or Yamaha C1 even have a built in MIDI interface. It has at least two ports (sockets) on it: MIDI In and MIDI out. A MIDI cable is required to link the MIDI In port on the interface to the MIDI Out port on an instrument, or vice versa. A third port, MIDI Thru, is sometimes present for connecting more MIDI devices.

Here is a brief description of the MIDI interface cards available for the IBM PC. Information is only up-to-date as at 1991. There are new products coming out constantly.

Roland MPU interface card

The industry standard MIDI interface for the IBM PC is the Roland MPU-401 released in 1984. MPU stands for MIDI Processing Unit. It is generally recommended, or one of its clones, because a great deal of software is available for it. The latest version of the MPU is the MPU-IPC Version 1.5A. It comes in two parts: a half sized expansion card together with a small external box. The box has a MIDI In and two MIDI Outs. The MPU is an intelligent interface. Using its own specialised commands, it can record into, and play notes from its internal 8-track memory buffer. It has an internal clock with a timing resolution of up to 192 ppq (part per quarter note). Using this clock it is able to provide an accurate metronome and handle tempo changes. Another version, the MPU-IMC is for the IBM PS/2 which uses micro channel architecture.

Music Quest

This is a company in Texas which produces MPU-compatible intefaces which also work in the intelligent mode and have features for adjusting parameters in case any hardware compatibility problems are encountered (port address and interrupt level). The basic model is the PC MIDI Card. It has no tape-sync facility, but can recognise MIDI time code. The MQX16 and MQX32 are higher models which offer SMPTE (facility to synchronise with film and television frames) and offer more features and channels.


Voyetra is a US company producing a wide range of MIDI basics and extras. Its MPU-compatible intrefaces work in intelligent mode and have genuine Roland circuits rather than copies of them. V4000 is the basic model and V4001 and V4001cs have additional synchronisation features.

Dr T

Dr T is a firm well known in the world of Atari, Commodore and Amiga. It does produce one MPU-compatible interface, the Model 1 which is a fairly basic card.

Midiers Land

The Midiers Land MD401 is a budget MPU-compatible interface. Its SM401 has some more features such as some on-board sounds.


A new product which is very competitive. For details please refer to the bulletin on this card in this BBS.

Sound Blaster Pro

Sound Blaster Pro can also act as a MIDI interface although the functions are limited and it is non-MPU-compatible. For details please refer to the bulletin on the MIDI Function of the Sound Blaster Pro in this BBS.

Roland LAPC1

This is a Roland MPU card with the features of a sound module equivalent to a Roland MT32 built in. It can produce sound on its own by receiving data from the computer. The addition of a MCB-1 connector box can give it the same capabilities as a MPU interface.