MIDI > MIDI Articles (PC / MAC / ATARI)

windows/PC midi interfaces (oldschool txt file from early 90s)




MIDI is an acronym for Musical Instrument Digital Interface, and basically
it’s a common digital data communications protocol used by all MIDI

If you look on the back of your unit and see MIDI IN and OUT ports (5 pin
DIN sockets labelled IN and OUT and/or THRU), you have MIDI capability.
How much or how little depends on the cost of the unit, its vintage, and
how few or numerous the many capabilities of the the MIDI Specification,
the manufacturer’s hardware/software implements. At a minimum, you should
at least be able to transmit note on and off data to/from your unit. This
alone is a powerful capability since it will allow you to connect a
computer to your MIDI keyboard and record and playback notes/songs using
MIDI software and a hardware interface in your computer.

What can you do with MIDI? Unbelievable things. We still don’t know all
the possibilities. It started out as a way to play one synthesizer’s
internal sounds from the keyboard of another synth, just by hooking the
two together via a MIDI cable. (From the MIDI OUT of the controlling
keyboard to the MIDI IN of the slave.) Over the past eight years since its
inception, MIDI and its applications have grown to include many very
interesting and useful capabilities such as sequencing, patch editing,
computer game sound enhancement, multimedia sound/music support, lighting
controls, and even transferring songs and sounds on telephone lines in
digital form across the world on networks such as MIDILink!

To take advantage of these capabilities, a computer becomes a very
desirable tool for easily manipulating all that power MIDI provides. But
how do you connect a computer to a piece of MIDI gear, or a whole MIDI
system, for that matter? No *appearant way is immediately visible for the
novice MIDI musician since those round, five pin DIN plugs used by MIDI
are foreign to computers. (with the exception of the Atari ST which has
built‐in MIDI ports)

The answer is easy ... just get a MIDI(/computer) Interface. Most all are
similar in form/fit to other interface cards such as bus mouse cards,
internal modems, video cards, etc., in that they plug into the PC
expansion bus and provide the proper electronic interface and external
connectors. (The 5 pin DIN “IN” and “OUT” sockets.) The more difficult to
answer question becomes _which_ card to purchase, and what are the
differences between them?

Let’s talk software for a minute. Unfortunately, unlike the
standardization in the MIDI protocol itself, standardization in interfaces
between MS DOS computers and MIDI are not universal.  Works somewhat like
modems. While most support one standard (i.e. Hayes AT command set), not
all MIDI interfaces are supported by all MS DOS MIDI software. The defacto
standard, similar to the Hayes analogy, is the “MPU‐401 compatible” MIDI
Interface. This was the first and only interface available in the
beginning, and thus it became the standard bearer. “MPU‐401” was the model
number Roland Corp. assigned to that initial design, and while it is no
longer made, improved clones compatible with that design now abound,
including improved models made by Roland. The reason this is important to
know, is that MS DOS MIDI software developers universally support the
large MPU‐401 user base, but non‐compatible MPU‐401 interfaces have a much
more limited software base from which to chose. Anyone who has owned a
non‐compatible Hayes modem will appreciate the importance of buying
hardware with a large software support base.

For those of you with unique hardware requirements, let’s first talk about
a few special cases involving special external MIDI interfaces. For
laptops or computers with no expansion slots available, there are external
serial and parallel port MIDI Interfaces available such as the MIDIATOR,
made by Key Electronics. Since this and most other external interfaces are
not MPU‐401 compatible, software support is more somewhat limited;
however, the interface manufacturers do provide some level of software
with their products. So it’s best to contact the manufacturer to find out
what software is provided or is available by 3rd party vendors. In
addition, be cautioned that because MIDI uses a 31.25kHz bandwidth, timing
tolerances, especially on serial ports designed for lower speeds, are very
critical at MIDI’s high baud rate with dense data. Check with the
manufacturer to make sure your particular brand/model computer works with
their external serial or parallel port interface.

Also, for PS/2 owners with MCA (micro‐channel architecture) buses, Roland
Corp has an internal interface called the MPU‐IMC which is MPU‐401
compatible. Shipments began in November of 1989 at a retail price of $350.
These units are specifically for MCA buss computers only.

For standard PC/XT/AT expansion buss card slots, there are many interfaces
available. Some are not MPU‐401 compatible such as the Mellotron MUART now
sold by Tandy, SDA (Sound Design Associates) MIDI Interface, CMS (Computer
Music Supply) CMS‐101, Brown‐Wagh SoundBlaster, the IBM Music Feature
Card, and others. Some of these cards have MPU‐401 compatibility options,
such as daughter boards, adapters, etc.

Manufacturer   | Model #    |MPU   | MIDI    | Notes |
| ATI Tech    | Stereo F/X    | no   | 1/1    | Compatible with SB. Reqs Adapter|
| Creative Labs   | SoundBlaster   | no   | 1/1    | Simultaneous I/O not possible |
| Creative Labs   | SB Pro    | no   | 1/1    | MIDI Adapter & Software Included|
| Creative Labs   | SB MicroChnl   | no   | 1/1    | Requires MIDI Kit |
| Creative Labs   | SB MIDI kit    | no   | 1/4    | Required by Soundblaster |
| Media Vision    | Pro Audio S    | no   | 1/1    | Requires opt MIDI adapter
| Mellotron    | MUART    | no   | 4/4    | Marketed by Tandy |
| SDA       | MIDI Int    | no   | 1/1    | Metronome out, FSK sync |
| IBM       | MFC       | no   | 1/1    | On board FB01 chip |
| Key Elec    | MS‐101    | no   | 1/1    | Connects to RS‐232 port |
| Key Elec    | MS‐103    | no   | 1/3    | RS‐232 3 independent OUTs |
| Key Elec    | MS‐114    | no   | 1/4    | Switchable baud rate, opt RS‐422|
| CMS       | CMS‐101    | no   | 1/1    | Upgrade avail to 404, 4‐OUTs |
| CMS       | CMS‐401‐II    |yes   | 2/2    | Model 2 has 2 sw/addr MIDI OUTs |
| CMS       | CMS‐444‐II    |yes   | 2/2    | SMPTE/FSK opt 4/4 cable |
| CMS       | CMS‐444‐EX   |yes   | 4/4   | SMPTE/FSK rack mount 4 THRUs |
| MIDIMAN   | MM‐401   |yes   | 1/1    | UART mode timer, metronome out |
| Music Quest    | MIDICard   |yes   | 1/1    | Metronome out |
| Music Quest    | MQX‐16    |yes   | 1/1    | Smart FSK(chase) |
| Music Quest    | MQX‐16S    |yes   | 1/1    | Adds SMPTE |
| Music Quest    | MQX‐32M    |yes   | 2/2    | Smart FSK, SMPTE, sw adrs outs |
| Roland    | MPU‐IMF    |yes   | 1/1    | Metronome out,supercedes 401 |
| Roland    | LAPC‐I    |yes   |    | Onboard MT‐32 equiv incl. |
| Voyetra    | V4000    |yes   | 1/1    | No tape sync |
| Voyetra    | V4001    |yes   | 1/1    | FSK tape sync |
| Voyetra    | V22       | no   | 2/2    | Sync to external MTC |
| Voyetra    | V22m       |yes   | 2/2    | Adds MPU‐401 compatibility |
| Voyetra    | V24s       | no   | 2/4    | Click detector |
| Voyetra    | V24sm    |yes   | 2/4    | MPU‐401 compat, SMPTE, click det|

FSK is an acronym for Frequency Shift Keyed time code. It is a set of
tones in the audible range suitable for recording by an analog tape
recorder. With FSK sync, you can synchronize the software sequencer to a
multi‐track tape recorder. However, you must start at the beginning of the
tape each pass. Smart FSK and SMPTE (Society of Motion Picture and
Television Engineers) time code contains “position” data, and the software
will “chase and lock” to whatever position you start at on the tape.

Most interfaces use the computer’s built in speaker to emit a metronome
“beep” to allow you to keep time to the music. Metronome out ports allow
you to amplify the signal through your sound system. This may be important
if you play at higher volumes since the computer speaker level is
generally low. However, if you have a drum machine that slaves to external
MIDI clocks, you can easily keep time with a simple drum pattern,
completely eliminating beeps from the computer.  Many people prefer this
method since beeps are pitched and are distracting when playing music in
another key.

Bundled Software Some manufacturers and dealers offer “package deals”
containing a MIDI Interface along with popular sequencing software. These
bundled deals are often a good way to save money since the prices are
lower than interfaces and software bought separately. Since the hardware
is somewhat user transparent with the exception of features such as outs,
sync, and metronome ... testing the software is key in making a decision
that will serve your individual needs.  For that reason, we make every
effort to keep demo programs of all the popular commercial software
packages available to you in our MS DOS DEMO library #5. Other demos for
other computers can be found in their respective file libraries here on
Sound Management.

While these package deals are constantly changing depending on current
hardware/software availability/popularity ... a typical example of a
bundled hardware/software package is the Voyetra MIDIPAK Plus (V‐4001
bundled with Seq+ MK I ver 3.0) for $249. This package usually has a
discounted dealer “street price” of somewhere around $190. Twelve Tone
Systems, publishers of Cakewalk, also bundle their software with the
MusicQuest MIDICard for well under $200. Often upgrade policies allow you
to trade up to more powerful software versions and/or interface
configurations for very reasonable costs, sometimes just the difference in
list prices.

Finding a package that suits your particular needs and budget is beyond
the scope of this file, but you will find many very friendly MS DOS MIDI
enthusiasts on in the IBM conference and from some of the various vendors
here on MIDILink.

So feel free to ask specific questions about products you are considering.
Nothing beats a candid report from an actual user, or the latest product
news right from the manufacturer.

Happy Music making!
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