Roland DiscLab CDX-1 Manual Del Usuario página 208

MIDI Implementado
How to calculate checksum (Hexadecimal number is shown with H)
Checksum is a value which lower 7 bit of the sum of address, size and checksum itself turns
to be 0.
If the address of the system exclusive message to be transmitted is aa bb ccH and data or
size is dd ee ffH,
aa + bb + cc + dd + ee + ff = sum
sum / 128 = quotient and odd
When odd is 0, 0 = checksum
When odd is other than 0, 128 - odd = checksum
MIDI Machine Control (MMC) Command, Information Field / Response
Reference
Commands Recognized
Command Action
01H STOP STOP
02H PLAY PLAY
03H DEFERRED PLAY PLAY
04H FAST FORWARD FF
05H REWIND REW
06H RECORD STROBE REC/PUNCH IN
07H RECORD EXIT PUNCH OUT
Commands Transmitted
Command Action
01H STOP STOP
03H DEFERRED PLAY PLAY
06H RECORD STROBE REC/PUNCH IN
07H RECORD EXIT PUNCH OUT
44H 01H LOCATE TARGET LOCATE
Valid Information Fields / Response
Information Field Interpret
01H SELECTED TIME CODE Current Time
08H GP0/LOCATE POINT Locator 1
09H GP1 Locator 2
0AH GP2 Locator 3
0BH GP3 Locator 4
0CH GP4 Locator 5
0DH GP5 Locator 6
0EH GP6 Locator 7
0FH GP7 Locator 8
4FH TRACK RECORD READY Track Status
* CDX-1 transforms the Information Fields GP0-GP7 which are written by the MMC
WRITE COMMAND (40H) to MEASURE/BEAT/TICK format data which accord with
current tempo and time signature, and then registers them to the locators 1–8.
208
Valid Commands
MOVE (FROM)
MOVE (FROM), MOVE (TO), WRITE
MOVE (FROM), MOVE (TO), WRITE
MOVE (FROM), MOVE (TO), WRITE
MOVE (FROM), MOVE (TO), WRITE
MOVE (FROM), MOVE (TO), WRITE
MOVE (FROM), MOVE (TO), WRITE
MOVE (FROM), MOVE (TO), WRITE
MOVE (FROM), MOVE (TO), WRITE
MASKED WRITE, WRITE