hd 44780 is not working


New member
I just bought a 2 x 20 white on bleu display hd 44780 compateble. i have seen it work and ik looked great. but now i have it all wired up and cecked it 4 times. but i can't get it working.

my OS is win2000 pro. i'm using dlportio with te program smartie. but i don't get anny text. i used crystal control with out dlportio and still nothing. and i used several other progs but all wont work with the LCD.

i also looked if it worked in win 98se but still the same problem

if i change my contrast i see 1 black line and nothing.

what can i do about this?
any body?
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CF Support

Under what conditions did you see it work?

99.999999999999% of problems with HD44780 to PC parallel port LCDs lie in the wiring.

4 times checking on the wiring may not be enough.

Good wiring guides for HD44780 compatible LCD's can be found:






You can also go to http://forums.bit-tech.net/showthread.php?threadid=5582 and search for "assuming alphanumeric" and you will find a short Q/A post on parallel displays.

Best of luck.


New member
thx I made a verry big mistage. i counted the pin's of the LPT connector wrong.

bu't now it's working fine manny thx:eek: