> I have checked the data and it just
> refers to the HD44780 for function which doesn't mention it 
> there is 100k pull down on the bus 

It does, in a very implict way. First it shows no connection at all to
the lower data bus pins when 4-bit mode is used (this is bad practice
unless some form of pull up or down is present), and in the electrical
section the strength of these pulls is documented.

> Anybody got any ideas???

Put a buffer inbetween. Or are there pull up/downs on all data pins or
only on D0..D3? If only on the lower pins you could use 4-bit mode.

Wouter van Ooijen

-- -------------------------------------------
Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: www.voti.nl/hvu
 

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist