APPENDIX
© E-mu Systems, Inc. 1985
Page 92
Enhanced by The Emulator Archive 2002 www.emulatorarchive.com
The words of greatest interest to the SP-12 relate to pitch and tempo. The SP-12
sounds can respond to different notes being sent over MIDI (see Section 6A);
therefore, drum sounds can be played by hitting individual notes on a MIDI keyboard.
If the keyboard sends velocity (dynamics) data, the SP-12 will respond to this data.
The SP-12 can also “slave” to tempo data being sent over MIDI from a master, or
serve as a MIDI master to which other MIDI devices refer for tempo information.
Dealing With “MlDlosyncracies”
There are certain compatibility problems between MIDI gear from different
manufacturers; however, many problems are created by operator error and/or a lack
of understanding bow MIDI works. If you transmit information on one channel and
have the “receiver” set up for a different channel, forget it. MIDI is quite unforgiving
that way...you can bit a bum note and not too many people will notice, but send a
computer a wrong number and it will most definitely notice.
MIDI is a lot of fun provided that you don’t get discouraged when things go wrong.
One of the major problems is “data clogging” of the MIDI data stream. If MIDI is
handling drum data, keyboard synthesizer data, timing data, and so on, an excess of
information can cause the system to slow down or possibly malfunction. If this
occurs, try to figure out what data can be “filtered out” of the MIDI stream. For
example, keyboard aftertouch information requires much data; filtering this out of the
data stream leaves more breathing room for other data, such as the timing
information received by the SP-12.
SMPTE
The Society of Motion Picture and Television Engineers adopted SMPTE time code
in order to synchronize audio to video. Basically, SMPTE is a digital code that is
recorded on audio tape or video tape, or “burned into” film. This code outputs time
information as hours, minutes, seconds, and “frames” (1/30th of a second intervals).
For synchronization, sophisticated machines “look” at the SMPTE time code tracks
on the audio and video machines to be synchronized, and correct the speed of one
unit vis-a-vis the other to maintain synchronization. These error corrections are very
subtle and are not noticeable.
The SP-12 uses SMPTE so that songs and sequences may be started at a specific
frame of time code. The SP-12 can also write SMPTE time code on tape.
