Apple MIDI Interface
| Apple MIDI Interface | |
|---|---|
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|
| The Apple MIDI Interface with its two MIDI cables (left) and serial cable (right), from Apple's 1988 dealer product art | |
| Manufacturer | Apple Computer, Inc. |
| Type | MIDI interface |
| Interface | Mini-DIN-8 serial port (Macintosh or Apple IIGS) |
| Compatible | Apple IIGS, Macintosh Plus, Macintosh SE, Macintosh II and other Macintosh models with mini-DIN-8 serial ports |
| Dimensions | About 2.92 × 2.08 × 1.31 in (74 × 53 × 33 mm) |
| Model | A9M0103[1] |
| Connectivity | One MIDI In, one MIDI Out (5-pin DIN) |
| Power | From the computer's serial port |
The Apple MIDI Interface is a small box that connects a Macintosh or an Apple IIGS to MIDI musical instruments through one of the computer's serial ports. It has one MIDI In and one MIDI Out, has no MIDI Thru, and takes its power from the serial port, so it has no power supply of its own.[2] Apple's specification article for it is dated January 1988.[2] In March 1988 Apple sent its music dealers a Professional Music Demonstration Kit built round a Macintosh Plus, the Apple MIDI Interface and an Ensoniq ESQ-1 synthesiser.[3]
Hardware
[edit | edit source]| Port | Connector | Cable length |
|---|---|---|
| MIDI In | 5-pin DIN | 2 m |
| MIDI Out | 5-pin DIN | 2 m |
| Serial | Mini-DIN-8 ("mini circular 8") | 46 cm |
Apple gives the box as roughly 2.92 in long, 2.08 in wide and 1.31 in deep.[2] The interface has no microprocessor. It cannot read or send SMPTE time code, which travels on separate audio leads, but MIDI Time Code already embedded in the MIDI stream passes through it unchanged.[4]
| Pin | MIDI In | MIDI Out |
|---|---|---|
| 1 | No connection | No connection |
| 2 | Shield ground | Shield ground |
| 3 | No connection | No connection |
| 4 | Interface enable | +5 V |
| 5 | Data in | Data out |
Connecting it
[edit | edit source]The interface plugs into either the printer port or the modem port of a Macintosh or an Apple IIGS. Some programs work with only one of the two ports, so check the program's manual. On the IIGS the serial port settings in the Control Panel may also need changing.[2] Apple's instructions are:[2]
- Run one MIDI cable from the interface's MIDI In to the instrument's MIDI Out, and the other from the interface's MIDI Out to the instrument's MIDI In.
- With the computer switched off, connect the serial cable between the computer and the interface.
- For a second instrument, run a cable from the first instrument's MIDI Thru to the second instrument's MIDI In, and so on down the chain.
Only the first instrument in the chain can send data back to the computer. With a keyboard controller and one sound module, the controller's MIDI Out can go to the interface's MIDI In and the interface's MIDI Out to the module, with nothing going back to the controller.[2]
Call-A.P.P.L.E. lists the Apple IIGS, Macintosh 512Ke, Macintosh Plus, SE and II as the computers it connects to. The 512K and earlier machines have a 9-pin serial port, and A2Heaven's compatible interface needs an adaptor cable for them.[1]
Software
[edit | edit source]On the Macintosh, Apple's MIDI Manager and Apple MIDI Driver came in the MIDI Management Tools package; version 2.0.2 also held PatchBay and Serial Switch. Apple treated the MIDI Manager as a developer tool. It runs under System 7.5, but Apple did not support it.[5] On the Apple IIGS, System 6.0.1 includes an Apple.MIDI driver alongside the MIDI tool sets.[6] The manual for the IIGS program synthLAB names the Apple interface as an example of the 1 MHz external interfaces it works with, and says MIDI is not available while AppleTalk is active.[6]
Faults
[edit | edit source]The interface has no power light, so a fault shows only as missing MIDI traffic. One case on the Applefritter forum, written up by the owner, shows what to check first.[6]
- Check the serial cable. Mini-DIN-8 serial cables come wired straight through (modem style) or crossed over (printer style), and they are hard to tell apart by eye. An Apple MIDI Interface that worked on a Macintosh SE/30 appeared dead on an Apple IIGS until its owner found he had mixed up his cables; with the right cable it worked on both. Check the wiring with a meter before suspecting the box.[6]
- Turn AppleTalk off on the IIGS. synthLAB's manual says MIDI is unavailable while AppleTalk is active.[6]
- Check that the program is set to the port the interface is plugged into.[2]
- Chain further instruments from the Thru socket of the first instrument, as the interface has no Thru socket of its own.[2]
Documentation
[edit | edit source]The archive.org item titled "Apple Documentation: MIDI Interface User's Manual" is Passport Designs' 1985 manual for its MH-01A and MH-02A MIDI cards for the Apple II and its MH-01C for the Commodore 64. It does not describe Apple's interface.[7]
Gallery
[edit | edit source]-
Apple's 1988 dealer art: Macintosh Plus, Apple MIDI Interface and Ensoniq ESQ-1
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Related pages
[edit | edit source]References
[edit | edit source]- ↑ 1.0 1.1 A.P.P.L.E. (Apple Pugetsound Program Library Exchange), "A2Heaven Releases Apple A9M0103 Compatible Midi Interface", Call-A.P.P.L.E. (read 4 October 2026). Names Apple's interface as the A9M0103 and lists the computers it connects to: Apple IIGS, Macintosh 512K Enhanced, Macintosh Plus, Macintosh SE and Macintosh II.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Apple Computer, Tech Info Library article 2474, "Apple MIDI Interface: Specifications", reviewed 20 January 1988. Copy at absurdengineering.org. Size, connectors and cable lengths, MIDI DIN pin assignments, no MIDI Thru, power from the serial port, use of either the printer or modem port, connection instructions.
- ↑ Apple Computer, How to Launch Your Musical Career, dealer marketing kit, March-April 1988, 21 pages. archive.org item how-to-launch-your-musical-career-apple-computer-marketing-kit-1988. Covering letter of 30 March 1988 (kit contents: Ensoniq ESQ-1 keyboard, Bose speakers, Apple MIDI Interface, RCA-to-1/4 in adaptors, software); reorder sheet (Apple MIDI Data Sheet, M3035); April 1988 letter on promoting the Macintosh Plus and Apple MIDI Interface; product art page.
- ↑ Apple Computer, Tech Info Library article 2728, "Apple MIDI: How To Make It SMPTE Compatible", reviewed 9 September 1988. Copy at absurdengineering.org. The interface does not handle SMPTE time code and contains no microprocessor; MIDI Time Code in the data stream passes unchanged.
- ↑ Apple Computer, Tech Info Library article 7631, "Apple MIDI Manager: Compatibility & Availability", created 21 April 1991, updated 25 October 1995. Copy at absurdengineering.org. MIDI Management Tools 2.0.2 contents (Apple MIDI Driver, MIDI Manager, PatchBay, PatchBay DA, Serial Switch); developer tool; compatible with System 7.5 but unsupported.
- ↑ 6.0 6.1 6.2 6.3 6.4 Applefritter forum, "Apple MIDI Interface", thread of December 2014 to January 2016 (read 4 October 2026). Community repair report: an Apple MIDI Interface that worked on a Macintosh SE/30 appeared dead on an Apple IIGS running synthLAB and MasterTracks Pro with the System 6.0.1 Apple.MIDI driver; the cause was the wrong kind of mini-DIN-8 cable (straight-through versus crossover). The thread quotes synthLAB's manual: any 1 MHz external interface such as the Apple MIDI interface works, and MIDI is unavailable while AppleTalk is active.
- ↑ Passport Designs, MIDI Interface Card User Manual & Technical Notes for Models MH-01A & MH-02A with Tape Sync for Apple //, //e & Model MH-01C for Commodore 64, 1st edition, March 1985. archive.org item MIDI_Interface_Users_Manual, catalogued there as "Apple Documentation: MIDI Interface User's Manual".