IconEdit Check Sum (Technical Docs)


Midi Quest Pro only


If there is a check sum routine for the SysEx, it will be run each time before the SysEx is sent out via MIDI (note: when using macros this must be a component of the macro). There are four parameters which control the Check Sum.

Type: there are thirteen predefined check sum types

0) Yamaha format 2's complement check sum

(sum bytes and take 2's complement)

1) Nibble format where checksum is divided and

COfs stored in two bytes COfs & COfs + 1

(combine nibbles, sum bytes, nibblize to


2) Nibble format

(combine nibbles, sum bytes, strip high bit,


3) K1 format

(sum bytes, add A5H, strip high bit, store)

4) Regular Checksum

(sum bytes)

5) 1's Complement check sum

(sum bytes and take 1's complement)

6) VZ1 format - combine nibbles and sum

7) K5 checksum format

8) SY22/35 Multi Bank checksum

9) SY22/35 Voice Bank checksum

10) Sum (sum bytes, strip high bit, store)

11) SY22 Voice checksum

12) K3 checksum (combine nibbles, sum, store nibbles)

13) 14 bit sum and store

NOTE: If the equipment uses a checksum other than one of these, communication will have to use a macro so that the checksum can be customized.

#Bytes - the number of bytes to perform the checksum on

- set to 0D if there is no checksum

- if using a Nibble format checksum, the number of

bytes operated on will be double that of the

number entered as a result of the nibble format

Start - the number of bytes from the start of the SysEx

where the checksum calculation will start

COfs - the number of bytes from the start of the SysEx

where the calculated checksum will be stored

Available in:

Midi Quest Pro


Midi Quest


Midi Quest Essentials


Midi Quest one