Bill 2

G'day! I've managed to make a sxformat message that controls the Master Level of my Roland Integra 7. I send it a number b/w 0 and 127 and a checksum calculated with an expr object (boy, did that hurt my little brain!) and it all works.

But having looked at the sxformat help file it seems that the checksum can be calculated within the sxformat object itself "using the expr function checksum". Does anyone know exactly how that can be done? I don't NEED to know, y'know? But if the help file says it can be done I'd like to give it my (actually, the forum's) best shot!

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midiout

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G'day! I've managed to make a sxformat message that controls the Master Level of my Roland Integra 7. I send it a number b/w 0 and 127 and a

checksum-within-sxformat-message-for-roland-integra-7

What, no sxformat or expr checksum gurus out there? I'm shocked!

one counts from 0 , so adress starts at 7th position in the list, data is at 11th...

rest is known - summ adress + data, pass through %128,

sxformat 240 65 16 0 0 100 18 2 0 0 5 / is $i1 / is 128-(checksum(7,11,1)%128) / 247

rest is known  - summ adress + data, pass through %128,
subtract the result



STOP PRESS: doing some testing right now. The following may all be cancelled.

Thanks for that, Source :-) and sorry for taking a while to reply. It's much clearer now but still doesn't quite make sense.

- The checksum function can be used as part of an expression. Didn't think of that. Ta!

- I could've just used the expr 127-(($i1+6)%128) without bothering with the checksum function. I was fixated on the 2nd tab in sxformat.maxhelp and didn't think of going back to the first tab to find that out. Oops!

- sxformat arguments are counted from 0, not 1. Makes a big difference! :o)

But the numbers you've given don't quite work with the Integra 7. It wants 0 to 127, not 1 to 128. So (checksum(7,11,1)%128) needs to be subtracted from 127, not 128. Easy. The part I still can't work out is that the address (2 0 0 5) makes the sum 1 too high; 6 works correctly but 7 doesn't.

The easiest solution for me is to forget the checksum function and just use / is 127-(($i1+6)%128) / instead. The off-by-1-but-only-when-using-checksum-function address can forever remain a mystery. Thanks again.

- The checksum function can be used as part of an expression. Didn't think of that. Ta!
- I could've just used the expr 127-(($i1+6)%128) without bothering with the checksum function. I was fixated on the 2nd tab in sxformat.maxhelp and didn't think of going back to the first tab to find that out. Oops!
- sxformat arguments are counted from 0, not 1. Makes a big difference! :o)

Thanks for that, Source. :-) And sorry for taking a while to reply - everyday life has no consideration for the importance of working in Max, does it?

You showed me a few little things there, but the checksum function still doesn't quite work. It's so close, though! Every input number b/w 0 and 127 is fine... except for 121, which results in a checksum of 128, which the Integra 7 doesn't like. But there's even less need to fully understand it now that I know the expression 127-(($i1+6)%128) does the job. The subtle vagaries of the checksum function can remain enigmatic while I return to another thread to ask you more questions. Thanks again!

Thanks Source - I learned a few handy things from that. :-)

Sorry for not replying sooner but I wanted to be clear first, and whenever I played with it I got inconsistent results. And I just found out that the Integra 7 will happily accept... wait for it... ANY checksum in the range 0 to 127. And there I was wasting time, thinking the expression with the checksum function had to yield the same result as the working one in the patch I posted. [Groan!]

So I've put a zero there and it works. But I'm a little bit wiser now. Thanks for your help.

it seems that expression in sxformat did not work.

by the way one does not need sxformat for sysex

You are welcome.
Good that it works at the end, but
it seems that expression in sxformat did not work.
this is formula that must work :

for Integra 7  :
sum of address 2 0 0 5  = 7 + Value 121 = 128 = 0
sxformat ignored last %128
I missed that.
by the way one does not need sxformat for sysex
much simpler is to use a message like
240 65 16 0 0 100 18 2 0 0 5 $1 $2 247

Yep, that's it - that patch works perfectly and makes sense. :-)

It's been a bit of a trip, though! I got the sys-ex message from the synth by changing the Master Level from its panel, assuming it'd be THE message to use for sending Master Level back to it. It included a checksum, hence my reading of "Calculating a Checksum" in the manual.

Then: sxformat object and help file, playing with expressions till I found one that worked, starting this thread in an attempt to find an even better way, more playing with expressions, finding that any random number b/w 0 and 127 works, more expressions, learning that a message can be used instead and finally finally finally finding (in the manual of all places) that the Integra 7 accepts the Universal Realtime System Exclusive Message "master volume". You know, the one it *doesn't* use when sending its master volume?

So after all that it's just a simple message, with no checksum, no sxformat, no expressions... just (for me) [pak 240 127 127 4 1 0 i 247]. Phew! I think I'll go shopping or something; I need a new monitor...

Thanks for your help, Source Audio! I've learned a few things from this and I reckon I'll be ready to make a synth editor one day. :-)

Ha ha, I had enough of such headscratchers along the path.

Checksum within sxformat message for Roland Integra 7?