it is serial, and we already tried using the serout command.
This is the code we used:
Pause 1000
start:
SEROUT portb.1, 1, [254,1] 'supposed to clear screen
pause 40
serout portb.1, 1, ["hello world"]
pause 400
goto start
end

in the book for the lcd, it says that the command for clear screen is 254 88,
but it doesn't work either