JLCooper MCS2 MIDI - Manual (Page 14)

More About Track Enabling
The MCS
2
has no knowledge of any track enabling done on
the machine itself, or of the status of the machine when the
MCS
2
is first powered on. The MCS
2
powers-up assuming all
tracks are not enabled.
The MMC specification combines the eight enable bits into one
command, so that the commands listed above show a
condition where all tracks had previously been un-enabled.
For instance, if tracks 1 thru 7 had been enabled, then an
Option Record is pushed, the resulting string of MMC would
be: F0 7F 7F 06 40 04 4F 02 60 3F F7, showing all eight
tracks enabled.
Of course, pushing a key for an enabled track will toggle the
track to un-enabled status.
The Wheel and Jog Button:
The Jog button changes the MMC command that the wheel
sends. When pressed, it also sends BF 1F 00 and BF 1F 7F
when released.
Approximately every 10 msec, the MCS
2
scans the wheel to
determine if the wheel has been moved during that period.
The way the MCS
2
deals with that information is different for
the Controllers and the MMC messages sent. Even though the
messages are described separately below for clarity, both types
of commands are sent together.
Wheel Controller Commands
The wheel sends controller 60h. The Wheel count is in form of
2's Complement with bit 6 as the sign bit. Positive numbers are
sent for Clockwise rotation. The number sent represents the
number of wheel counts accumulated since last transmission
(that is, a Relative position count), much like what a mouse
transmits. The resolution is approximately 180 counts per
revolution, and transmissions are sent at about 10 millisecond
intervals when wheel is being turned.
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