Author Topic: OMS (article, dec 1995)  (Read 1334 times)

Online chrisNova777

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OMS (article, dec 1995)
« on: July 29, 2017, 05:51:30 AM »

The Open MIDI System was developed by Opcode to make MIDI connections and routing simpler for musicians using the Macintosh. OMS acts as a central MIDI driver to communicate with MIDI hardware via a standard serial port connection, and provides professional quality timing services (developed by Steinberg and Opcode) for synchronising events.

Using the OMS Setup application, you specify which MIDI devices are attached to your MIDI interface, which MIDI channels they can receive on, whether they can send or receive synchronisation data, which socket (or port) each MIDI device is connected to (in the case of of a multi-port interface), and so on. OMS also allows you to route MIDI and sync data between two or more OMS-compatible applications running at the same time on your Mac.

Having completed the procedure described above, next time you ran an OMS-compatible MIDI sequencer, you would be able to make a list of all the devices in your MIDI setup available for use within your sequencer. Then, for instance, instead of having to choose, say, MIDI output port 3 on your interface and MIDI channel 1 for your DX7 on a particular sequencer track, you simply specify that a particular sequencer track will play your DX7! This is much better than having to try to remember which device is on which port and channel, as you have to do with non-OMS-compatible sequencers.

Another great feature of OMS is the ability to use a patch editor/librarian such as Opcode's popular Galaxy, to 'interrogate' your MIDI devices and have them send all their patch data via MIDI to your Mac. Once in the computer, you can save your patches onto disk, so you might have a file for your DX7 patches, another for your Proteus, and so on. This is very convenient, as you may want to change the sounds in your instrument's user-memory locations tomorrow, and come back to your current project another day.

OMS allows fully-compatible software, such as Opcode's Vision sequencer, to 'Subscribe' to a Galaxy file so that the list of patch names for a device will be made available for use within the sequencer software, just as OMS Setup data is made available to the sequencer. Now, instead of entering a MIDI Program Change number, you can select the patches in your instrument by name.

Third-party manufacturers like Steinberg, Digidesign, Passport Designs, Roland, Lexicon, Mackie, and Emagic are adopting OMS in increasing numbers -- although there is a similar system available from Mark Of The Unicorn, called the FreeMIDI System. This only works with MOTU products, and no other third-party manufacturers that I am aware of have implemented FreeMIDI as yet.

Yet another MIDI system with some similarities is Apple's own MIDI Manager software, which allows routing of MIDI data between MIDI Manager-compatible applications and to external devices. This software is not as efficient or as full-featured as the Opcode or MOTU systems, and is not normally recommended for professional work.

There have been some (very sensible) suggestions that Apple, Opcode, MOTU, and all the third-party MIDI software manufacturers should agree on one system to be adopted by all, to provide proper compatibility between all Macintosh MIDI software, perhaps with Apple providing the base level of this with a re-written MIDI Manager, and others providing the higher levels of functionality.

In line with this suggestion, Opcode recently announced that they have agreed to incorporate support for OMS into QuickTime, so that together, OMS and QuickTime will allow you to route QuickTime MIDI tracks to external MIDI devices. Full OMS compatibility is expected to be incorporated into QuickTime by the end of 1995. Steinberg and Emagic have also both added support for OMS, so this leaves MOTU standing outside with their FreeMIDI System.