Datadisk Functions; Section 4 Datadisk Functions; Theory Of Operation; System Exclusive - Alesis Data Disk Reference Manual

DATADISK FUNCTIONS

SECTION 4
DATADISK FUNCTIONS

THEORY OF OPERATION

SYSTEM
EXCLUSIVE
is able to work because the data is stored in the form of
DATADISK
System Exclusive (or sysex) files. System Exclusive is the unique
way that each manufacturer identifies its own particular data. This
allows data from one manufacturers equipment not to be mistaken
for another manufacturers when it is sent and stored.
When is in the Receive mode, either the first byte, or the
DATADISK
first three bytes, of information received is the manufacturer ID. In
most cases, will identify both the brand and model of the
DATADISK
equipment that it receives the system exclusive data from. If the
data is from an unknown manufacturer, will display "ID
DATADISK
xxH" for 1 byte IDs or "xxxxxx" for 3-byte ids (where xx or xxxxxx is
the manufacturer ID number in hexidecimal) instead of the
manufacturer's name. This will not confuse how the data is stored
by or loaded by the unknown piece of equipment,
DATADISK,
however.

RECEIVE MODES

normally receives data in the Receive One Sysex mode.
DATADISK
After the manufacturer ID bytes identify the unit, begins
DATADISK
storing data to disk and continues until it receives an End System
Exclusive command. Some synthesizers or MIDI devices will send
multiple messages, one after the other, which will
DATADISK
recognize and still save under the same file as long as there is no
more than 1/2 second delay between the end of one message and
the beginning of the next.
If there is more than 1/2 second but less than 1 second, then
will have stored the first file but will not have had enough
DATADISK
time to store the directory of that file before the next set of MIDI
messages arrive. When this occurs, will display "MIDI
DATADISK
OVERFLOW" and suggest that you use Receive Mult mode.
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