hi,
On some LCD displays the first 8 character locations and the second 8 locations have be addresses separately.
Assume its a 2 line by 16 character LCD
Use the first line address for 1 to 7 [ on mine its 80h]
and the second line address for 8 to 16 [ and 90h]
If you cannot locate the address, do the following test.
Start writing the 'alphabet' characters from the first location and write to the LCD say, a total of 100 characters.
You should be able to determine what the address of the locations 8 to 16 is.
Do you follow.?