converting dec to hex for ird

dredged through the forums and found a little info but still not sure i am getting the right set of characters
my 4001 has a nagra serial code of 12 characters NN NNNN NNNN NN
a couple of threads say drop the first 2 numbers then use the next 9 and convert to hex
i get 9 characters starting with a 3 and containing 7 characters
if i use the last 10 numbers i get a hex with 8 characters but starts with 27
if i use the first 10 numbers i get a hex with 8 characters and starting with 12 which i understand is what i should get, but i don't seem to be using the right set of numbers to get it ????
is the last option correct?
does the choice of numbers depend on the box?

m8 use this

http://www.world-of-digital.com/forums/showthread.php?t=35844

o just realised u only have 1 post, read the rules m8

You could open up your box and look at the label on the SCART socket screening can .

dont need a min post count now has been this way for a while

rickparmar
many thanks, that prog matched what i got using the first 10 numbers

lol sorry davidh,

anothr way to get your ird is by using the top no on th double barcode sticker on the bottom of the box ie it starts noxxxxxxxx disgard the no and feed the next nine numbers into the windows calc in decimal and select the hex box and that will give you the ird.