If your LCD uses Hitachi 44780 'standard' commands, and is a 20 char x 4 line, you might find the following to be useful:

Line Address offset
1 00h
2 40h
3 14h
4 54h

And don't forget to add 80h to the offset for the Data RAM instruction.

If you don't have a data sheet on your controller chip, search the web for your IC part number(s).

Hitachi data sheet for the HD44780 is 60 pages. Lots of help there.....

When you get things working, you should really enjoy the LCD module. I usually use the bottom line for a menu list (with 4 pb switches directly under, matching the alignment of 4 brief menu items; works great.

Harley