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PC MIDI Interface
Published March 1994

PC users get a look in on the sophisticated MIDI add‑on market with a multi‑port, sync‑generating unit from Mark of the Unicorn. Steven Helstrip catches the MIDI Express.

Over the last two to three years there has been an explosion in confidence, from manufacturers and musicians alike, about Windows and the 'MIDI PC'. Whilst Cubase, Cakewalk, and Cadenza have headed software sales throughout Europe, the market for MIDI interfaces has been dominated by the likes of Music Quest, Voyetra and the now discontinued CMS range. When compared with equivalent offerings for the Mac, however, PC interfaces appear somewhat outdated, and limited by their number of ports and their lack of MIDI data routing capabilities.

As sequencer technology marches forward, the need for a better, more flexible interface becomes apparent. To fill this gap in the market, Mark of the Unicorn (MOTU), a name synonymous with 'Macintosh' among musicians, has ventured into the PC market with MIDI Express PC — a 1U, 19‑inch rackmount unit with six MIDI inputs, six MIDI outputs, SMPTE, and extensive software support for cable routing and MIDI patching.

Express Service

The heart of the MIDI Express is a half‑length, 8‑bit AT card which houses the brains for the interface. On the rear of the card is a connector for the rackmount unit and a serial port for direct connection to a Mac, should you have one. Supplied with the unit came a generous 7‑foot cable connector, MIDI Express Console for Windows, and drivers for DOS. Installation proved to be a simple task — in fact, it was more difficult removing the unit from its packaging, simply because I didn't have a pair of scissors to hand to cut it free from the security band! All told, MIDI Express was up and running within about 10 minutes of getting it home.

On the face of the now‑rackmounted unit, 12 LEDs monitor MIDI activity from each of the six MIDI Ins and Outs, and additional LEDs indicate SMPTE operation and Jam sync. Happily the unit's power is supplied directly from the PC, eliminating the need to find yet another power socket in the studio. As with MOTU's MIDI Time Piece (MTP), MIDI input 6 and MIDI output 6 have been duplicated on the front panel for convenience, useful for temporarily adding equipment to your MIDI rig. The panic button (All Notes Off) on the right of the front panel is there to put an end to those irritating hanging notes — it works by sending Note Off commands to each and every note on every channel for all six ports; this procedure can also be initiated from within the included software.

As you'd expect, the MIDI ports are positioned at the rear of the rack unit, as are three quarter‑inch phono jacks for SMPTE in/out and a programmable footswitch input. From within the software, the footswitch can be assigned to send MIDI messages to any instrument in your setup, the idea being that you can use the unit in a live situation to set up your instruments by assigning the pedal to trigger program change messages, and/or send a start command to your sequencer. The footswitch port also doubles up as an audio to MIDI trigger input; connect an audio source here and you can trigger drum samples or create tempo maps for your sequencer from a live click track.

The diminutive appearance of the MIDI Express belies the power within it. Compared with MOTU's own MIDI Time Piece II, this thing is tiny. The fundamental difference between the two is that all of the Express' functions are initiated from within its software and much of the processing comes from the card; with the MTP II, much of the necessary setting up is executed from the front panel.

MIDI Express Console

Upon installing the Express Console (the software control centre), you're met with the configuration window — a user‑friendly diagram to display I/O address. Should there be any IRQ conflict, the software prompts you to change hardware settings — re‑configuring DIP switches on the card and then making the necessary changes to the Windows MME driver.

The Express Console is all about working with setups. In simple terms, a setup describes how the MIDI express should handle all incoming and outgoing data. This includes re‑channelling, routing to any of six outputs, MIDI muting (filtering) and sync settings. The default setup is for use with software capable of addressing all six outputs (Cubase, MaxPak, for example); all inputs in this case are routed directly to the computer. Other presets include a setup for live playing where each of the inputs are routed to all outputs (excluding the source, to prevent MIDI loops), and 'Seq16' — a setup for use with notation packages which can often only address a single port (16 channels). Setups can be saved to disk to recall at a later stage. Incidentally, the unit which I reviewed was not MPU‑401 hardware compatible, but Sound Technology assured me that by the time you read this, compatibility will have been implemented.

Creating your own setup is done with the help of various edit windows within the package. The cable routing window is probably the easiest of all to get to grips with; inputs are named down the left of the window, and outputs down the right. When you select PC and/or Mac (port B) to be incorporated within your setup, icons appear to the centre of the screen to represent whichever is chosen. You connect devices to each another by drawing lines between them, which the software thoughtfully tidies up. Double clicking on any line calls up a dialogue box where you can specify which channel is to be routed; the default setting is all channels routed.

In the Event Muting window, any type of MIDI data can be filtered out on any channel or from any port when either going into or coming out of the MIDI Express. The input filter mutes selected events before they enter the MIDI Express, and the output filter swallows up events just before they are transmitted. Data types are separated into two categories: Channelised Events, and System Messages — which include active sensing, song select and tune request. By first selecting the event type to be filtered, you can then select any of the 64 check‑boxes on a grid which represents all input/output channels. All channels are selected when a system message is muted.

SMPTE time code can be generated in all formats from the SMPTE Controls window at eight user‑selectable output levels. The Express will 'freewheel' when SMPTE source code disappears and will write fresh code when locked to an incoming signal (Jam Sync). This function is handy for extending existing time code on tape by locking a time code generator to the existing code. If you have a Mac connected to port B, it can be 'slaved' to the MIDI Time Code (MTC) generated by the MIDI Express. When the PC locks to time code, the green light on the front panel glows steadily while the red Power/Tach light flashes regularly each second. No other interface I know of offers anything like this amount of flexibility at this price.


When Mark of the Unicorn announced MIDI Time Piece II for the PC, I must admit I was quite excited, until I saw the price — £749. Because the MIDI Express PC has been built solely for the PC, costs have remained low, yet no compromises have been made on quality. The hardware itself may not offer the same level of flexibility as the MTP II — for example, there are no transpose features — but much of this can be set up within your music application. However, it's not possible to have more than one MIDI Express PC within your setup allowing for more than six outputs (96 channels).

I see the release of the MIDI Express PC as another sign that manufacturers have finally begun to take the PC seriously as a music computer; I look forward to the release of more 'professional' PC‑related equipment onto the market.


  • Six MIDI outputs offering 96 addressable channels.
  • Good cable routing features.
  • SMPTE/Jam indicators and Panic Button on the front panel.
  • Serial port for direct connection to a Mac.
  • Available in 'Notebook' form, connecting via serial port.
  • The price.


  • Only one unit can be used, giving a maximum of 96 MIDI channels.
  • The software operation isn't always as obvious as it might be.
  • Unable to send a setup in the form of a system exclusive message direct from a sequencer.


An excellent and flexible piece of equipment that combines a multi‑port MIDI interface, MIDI router and comprehensive sync unit in one affordable box.