serial in data needs nib

[cncmachineguy]

I am not sure what you are asking. Do you mean when you receive first byte and it's 9, then the second byte is D, you want to put these together as 1 byte 9D?
To do that try this:

byte1 var byte
Byte2 var byte
Result var byte
Byte 1=byte 1<<4 ' shift low nibble to high nibble
Result =byte1 + byte2

Now if this is not the question, can you please explain more?