Appendix A: Midi Basics - Yamaha PORTATONE PSR-400 Owner's Manual

MIDI, the Musical Instrument Digital Interface, is a world-
standard communication interface that allows MIDI-compat-
ible musical instruments and equipment to share musical infor-
mation and control one another. This makes it possible to cre-
ate "systems" of MIDI instruments and equipment that offer
far greater versatility and control than is available with iso-
lated instruments.
The PSR-400/PSR-500 MIDI
Connectors
The PSR-400/PSR-500 MIDI IN connector receives MIDI
data from an external MIDI device which can be used to con-
trol the PSR-400/PSR-500. The MIDI OUT connector trans-
mits MIDI data generated by the PSR-400/PSR-500 (e.g. note
and velocity data produced by playing the keyboard).
Simple MIDI Control
Most MIDI keyboards (including the PSR-400 and PSR-
500, of course) transmit note and velocity (touch response)
information via the MIDI OUT connector whenever a note is
played on the keyboard. If the MIDI OUT connector is con-
nected to the MIDI IN connector of a second keyboard (syn-
thesizer, etc.) or a tone generator (essentially a synthesizer
with no keyboard), the second keyboard or tone generator will
respond precisely to notes played on the original transmitting
keyboard. The result is that you can effectively play two in-
struments at once, providing thick multi-instrument, sounds.
The PSR-400/PSR-500 also transmits "program change" data
when one of its voices is selected. Depending on how the re-
ceiving device is set up, the corresponding voice will be auto-
matically selected on the receiving keyboard or tone generator
whenever a voice is selected on the PSR-400/PSR-500.
PSR-400/PSR-500

APPENDIX A: MIDI BASICS

MIDI keyboard
or
tone generator
The PSR-400/PSR-500 is capable of receiving the same
MIDI data, so a second MIDI keyboard connected to the PSR-
400/PSR-500 MIDI IN connector can be used to remotely play
the PSR-400/PSR-500 and select voices as required.
MIDI Keyboard
MIDI Sequence Recording
The same type of musical information transfer described
above is used for MIDI sequence recording. A MIDI sequence
recorder can be used to "record" MIDI data received from a
PSR-400/PSR-500, for example. When the recorded data is
played back, the PSR-400/PSR-500 automatically "plays" the
recorded performance in precise detail.
PSR-400/PSR-500
Note: Never use MIDI cables longer than about 15 meters, since
cables longer than this can pick up noise which can cause data
errors.
MIDI Bulk Dump
MIDI bulk dump operations allow large amounts of MIDI
data to be transmitted from one device to another. The entire
contents of the PSR-400/PSR-500 PAGE MEMORY, for ex-
ample, can be dumped to a second PSR-400/PSR-500 or to a
bulk storage device such as a MIDI data recorder or MIDI
computer.
PSR-400/PSR-500
PSR-400/PSR-500
PLAYBACK
RECORD
MIDI sequencer
MIDI data recorder
37