Roland PCR-30, PCR-50, PCR-80 3. Bulk dump, 4. Supplementary material

MIDI implementation

3. Bulk dump

Bulk dump allows a large amount of data to be transferred in a single operation. For example, this can be used to store all settings of a device into a computer or sequencer.

On the PCR-30/50/80, a bulk dump will be transmitted when you execute the Bulk mode operation BULK TX. The bulk dump is transmitted as several exclusive messages.

Address	Parameter	Packets
00H, 00H, 00H, 00H--00H, 00H, 1A, 7F	Current memory	27

*You must leave an interval of at least 40 ms between each exclusive message.

*In the case of ALL BULK, the contents of memories 1--F will be transmitted as the current memory, consecutively from memory 1 through memory F. After transmitting one set of bulk dump data, you must leave an interval of at least 500 ms.

*Please be aware that if you modify the data dumped from the PCR-30/50/80 by changing the order in which the exclusive messages are transmitted, by inserting other messages between the system exclusive messages, or by speeding up the timing of the transmission, the data may not be set correctly when the PCR-30/50/80 receives it.

What is the decimal expression of 5AH?

From the preceding table, 5AH = 90.

What is the decimal expression of the 7-bit hexadecimal value 12 34H?

From the preceding table, 12H = 18, and 34H = 52.

Thus, this is

18 x 128 + 52 = 2356

What is the decimal expression of the nibble-expressed value 0A 03 09 0D?

From the preceding table, 0AH = 10, 03H = 3, 09H = 9, and 0DH = 13.

Thus, this is

((10 x 16 + 3) x 16 + 9) x 16 + 13 = 41885

<Example4> What is the nibble-expressed value of decimal 1258?

1258 ÷ 16 = 78 (quotient) ... 10 (remainder)

78 ÷ 16 = 4 (quotient) ... 14 (remainder)

4 ÷ 16 = 0 (quotient) ... 4 (remainder)

From the preceding table, 0 = 00H, 4 = 04H, 14 = 0EH, 10 = 0HA. Thus, the nibble-expressed value is 00 04 0E 0AH

4. Supplementary material

●Decimal and Hexadecimal table

(An “H” is appended to the end of numbers in hexadecimal notation.)

In MIDI documentation, data values and addresses/sizes of Exclusive messages, etc. are expressed as hexadecimal values for each 7 bits.

The following table shows how these correspond to decimal numbers.

Dec.	Hex.	Dec.	Hex.	Dec.	Hex.	Dec.	Hex.

0	00H	32	20H	64	40H	96	60H
1	01H	33	21H	65	41H	97	61H
2	02H	34	22H	66	42H	98	62H
3	03H	35	23H	67	43H	99	63H
4	04H	36	24H	68	44H	100	64H
5	05H	37	25H	69	45H	101	65H
6	06H	38	26H	70	46H	102	66H
7	07H	39	27H	71	47H	103	67H
8	08H	40	28H	72	48H	104	68H
9	09H	41	29H	73	49H	105	69H
10	0AH	42	2AH	74	4AH	106	6AH
11	0BH	43	2BH	75	4BH	107	6BH
12	0CH	44	2CH	76	4CH	108	6CH
13	0DH	45	2DH	77	4DH	109	6DH
14	0EH	46	2EH	78	4EH	110	6EH
15	0FH	47	2FH	79	4FH	111	6FH
16	10H	48	30H	80	50H	112	70H
17	11H	49	31H	81	51H	113	71H
18	12H	50	32H	82	52H	114	72H
19	13H	51	33H	83	53H	115	73H
20	14H	52	34H	84	54H	116	74H
21	15H	53	35H	85	55H	117	75H
22	16H	54	36H	86	56H	118	76H
23	17H	55	37H	87	57H	119	77H
24	18H	56	38H	88	58H	120	78H
25	19H	57	39H	89	59H	121	79H
26	1AH	58	3AH	90	5AH	122	7AH
27	1BH	59	3BH	91	5BH	123	7BH
28	1CH	60	3CH	92	5CH	124	7CH
29	1DH	61	3DH	93	5DH	125	7DH
30	1EH	62	3EH	94	5EH	126	7EH
31	1FH	63	3FH	95	5FH	127	7FH

*The decimal expression of the MIDI channel, program change, etc., is one greater than the decimal value shown in the table above.

*The hexadecimal expression for each 7 bits allows a maximum of 128 steps (0--

127)to be expressed by one byte of data. Multiple bytes are used if the data requires greater resolution than this. For example, a value expressed by two 7- bit bytes “aa” and “bbH” would be aa x 128 + bb.

*In the case of signed (+/-) data, 00H = -64, 40H = +/-0, and 7FH = +63; i.e., a value 64 less than the decimal value shown in the above table is used. In the case of a two-byte value, 00 00H = -8192, 40 00 = +/-0, and 7F 7F = +8191. For example, a value of “aa” and “bbH” would have a decimal expression of aa bbH - 40 00H = aa x 128 + bb - 64 x 128.

*In the case of data indicated as “use nibble data,” hexadecimal expression in 4- bit units is used. A nibble-expressed value of the two bytes 0a and 0bH would have a value of a x 16 + b.

●Example of an actual MIDI message

<Example1> CE 04

CnH is the Program Change status. “n” is the MIDI channel number. EH = 14, and 04H = 04. Thus, this is a program change message on MIDI channel 15, for program number 05.

●Checksum calculation

In order to verify that the message was received correctly, Roland exclusive messages (RQ1, DT1) add a checksum following the end of the data (before the F7). The checksum value is determined by the address and data (or size) of the exclusive message that is transmitted.

❍Calculating the checksum

(“H” has been added following hexadecimal values)

The checksum is a value that results in a lower 7 bits of 0 when the address, size, and checksum itself are added together.

Specifically, the calculation will be as follows when the exclusive message you want to transmit has an address of aa bb ccH and data or size of dd ee ffH.

aa+ bb + cc + dd + ee + ff = total total ÷ 128 = quotient ... remainder 128 - remainder = checksum

*However, as an exception, the checksum for a remainder of 0 is not 80H but rather 00H.

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