Progress!
I have exhaustively gone through all house and unit codes and discovered there is a pattern. I apparently skipped a bit when I typed in the pattern yesterday.
A1 ON is 00101010110011001101010000...
Lets expand that: 00101010110 0110 0110 1010000...
In all patterns the first 11 bits have remained the same. Bits 12-15 are the unit code, and bits 16-19 are the house code per the X10 Technical Note.
Command codes are more difficult because I don't see how to make the WM100 issue the full set of 16. I did check ON, OFF, Bright, Dim, ALL ON, ALL OFF, and a pre-set dim. They changed bits 21-29, but the patterns do not match the X10 protocol. The basic commands use bits 22-25, and a pre-set dim command also used bits 26-29.
1000 - ON
0100 - OFF
1110 - ALL OFF
1101 - Bright step
0011 - Dim step
ALL ON just sequenced through individual ON commands for all lights even when on the same house code.
Jeff