[Icom] ICOM 2100H Programming Information?

[icom@mailman.qth.net]

I have been burning the midnight oil trying to determine 
how the checksum is calculated for the channel data 
transmitted to/from the icom 2100H. Has  anyone cracked 
this already? I know what all of the other content is 
and this  is between  me and writting my own programming 
SW. 

I  figure the best clue  comes from blocks  that are 
very  similar as shown below. Each starts with a 
preample of ~~nnd and ends  with }

B9, 99 and 79 are the checksums for these three blocks. 
These decrease by 2 in the upper digit as the only 
change in the data is an increase in the upper 2nd digit 
of the block ID (72, 74, 76) 02. I sure would appreciate 
hearing  from anyone who knows  the algorithm.

Also - can someone who has the DOS version of the 
cloning  SW tell me what the procedure is during the 
setup. The SW says it  must recognize the rig  version 
number. Does DOS version 1.0 work with any 2100H? Do I 
put the rig in clone out during the setup?

I can read data from the 2100 using an ADMS cable from 
Yaesu and  Hyperterminal, so I think this cable is OK. 
However, during setup or when I try to read or write I 
get a message saying that the transceiver is not 
responding. Any hints? Please include my direct address 
on the reply. I subscribed to the list, but I  have not 
gotten any email from it yet and may not be properly 
subscribed.


~~nnd0720200000000000000000000000000000000000000000000000
000000000000000000B9}
~~nnd0740200000000000000000000000000000000000000000000000
00000000000000000099}
~~nnd0760200000000000000000000000000000000000000000000000
00000000000000000079}

The 8 bit equivalent of the preamble characters are:

~ = 254
n = 238
d = 228