the code I use are similar, you can try to adapt.

for the Hitachi HD44780 the decimal 254 represent the low RS then you need ot receive the line # as 128 line #1, 192 line #2, 148 line #3, 212 line #4

sEROUT2 lcd,baudR,pace,[254,128,"ABCDEFGHIJKLMNOP"] ' Line 1 16 Char


as for Richard code , for the Back Light he's using a toggle on,off with b1. (by receiving b1 turn On, then again turn Off)