Aratti,

Thanks for your reply.

1. the centre tap of the pot is connected to the contrast pin and does affect the contrast of the display but in an intermittant fashioin that changes with programming the PIC - It seems as if I've got the pin-out wrong, hence my concern that the data sheet on the Futurlec site is not the correct one.

2. I agree with you that the Spec sheet of the 4X40 LCD on the Futurlec USA site shows only one ENABLE pin but it also shows rows 1/3 and 2/4 as having the same addresses (starting at $80 and $C0) - this would only work if there were separate ENABLE pins for lines 1/3 and 2/4.

3. On the JDH site I can't find the JDH404A1 but the JDH404 and the JDH404A both show two ENABLE pins - hence my concern that the vendor's (Futurlec) spec sheet is wrong.