What i meant was:
convert the column value (e.g. 00000100b) into a hex value(or BCD).
in this case the 3rd column is selected, so your value is 02h.
if it was the 7th column the value would be 06h.
an example:
key in 3rd column an 5th row is pressed:
you will get those values:
column 00000100b(convert to 02h)
row 04 BCD
now you calculate: row*8+column
and thats the number of the key.
second possibility:
you told me that you have got the number of the key in BCD
just convert that number to a hex value because the access to the
lookup table is impossible with the BCD byte of the key
Christian