Emu XL-7 & MP-7 User's Group

Hi, Keith.

I have not done this on the Proteus line, but in other software I 
did (decades ago), I just added the values in the relevant locations 
based on 7 bits (ie., from 0x00 to 0x7F; next number is 0x00; that 
is 0x7F + 0x01 = 0x00). I then subtracted the value from 0x80 and 
the result was my checksum. I just assumed all midi checksums worked 
the same way. Is that the same as doing XOR?  Hmmmm. I guess it 
would be, wouldn't it? The question remaining is this: Is it based 
on 7 bits? (I would assume so.)

If I am right and I wanted to test it, I'd add all of the numbers 
from the 7E through the 388 bytes and figure out what I have to add 
to make it 0.

What happens if you do a bulk tuning dump from the front panel, add 
a few numbers to the frequency values, subtract an equal number from 
the checksum, and send it back to the E-Mu? (I may try this later.)

--Steve

--- In xl7@yahoogroups.com, "Keith Young" <emigr8@...> wrote:
>
> I am trying to use single note change and bulk upload and I cannot 
get 
> them to work. I thought the upload might be my checksum 
calculation, so 
> I tried getting a download to see if I could replicate the number 
> generated by the Proteus module, but I can't. Worse, the MIDI spec 
and 
> the Proteus manual includes different parts of the message in the 
> checksum calculation. I can't get the single note ones to work 
either 
> and these don't have a checksum in them so it may be wrong about 
what I 
> am expecting to happen.
> 
> If anyone has any code (or even a binary SSNC or Bulk dump) that 
works 
> I would be grateful.
> Thanks,
> Keith
>