concatenate nibbles?

[Possemo]

Hi, I am stuck on a problem reading MKS-70 Bulkdumps. The Roland MKS-70 seems to “obfuscate” the Patch Parameters in the way that it uses 96 Bytes to represent 48 Bytes. On the 96 Bytes only the lower Nibbles are used. Two pairs of lower Nibbles are representing a Byte. So the easiest way would be to concatenate the Nibbles. Is there an easy way to to this?
Thanks for reading.

[Possemo]

Tried somthing out that I found somewhere:

SysexByte1 = 5
SysexByte2 = 7

upper = SysexByte1
upper = 16*upper
if upper > 127 then upper = upper - 128 end
console (string.format ("upper=%d", upper))

lower = SysexByte2

combi = upper+lower
console (string.format ("combi=%d", combi))

could this do the trick? the upper 4 bits are always 0000 so we just have to convert the upper component. For this test i used no variables, assuming the sysex bytes were converted to decimal before.

[atom]

You can do bit operations using the bitop module included in Ctrlr/lua
http://bitop.luajit.org/

[Possemo]

Thanks atom, looks nice. If my subroutine does not work I will try Bitop.

[Author]

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