> So I want to send a controller 98 with a value of 01100002, for example, > right?

I don't understand your notation... What's that '2' doing in a what looks like binary ?

A little example. Say you want to use Principal 8' and Octave 1' in the 'I' division. These are stops 0 and 3 in group 2.

These are the four values you need to send for controller #98:

 binary     hex     dec      
 ------------------------------------------------------------ 

 01000010   0x42    66    m = 00, g = 010, switch off all stops in group #2
 01100010   0x62    98    m = 10, g = 010, select group #2, mode 'switch on'
 00000000   0x00     0    bbbbb = 00000, switch on stop #0
 00000011   0x03     3    bbbbb = 00011, switch on stop #3  

-- FA