I got this 24x2 lcd screen from some place for 15 bucks a couple of moonths ago. It's based on the HD44780 chip. I attached it to the parallel port wia a wiring diagram, and it seems to be acting a little funny. I have gone over, and over the wiring, and it seems to be fine. When I use some lcd test programs, they seem to find the lcd just fine, but I can not see anything displayed on the scree, it just stays completely black. I think it's something to do with the contrast, as it's all black, as opposed to off. The lcd drive voltage is 0 to -5 (pin used to control contrast) I connect it up to ground, which should work fine. I think the problem might actually be elsewhere. I would appreciate some help here, as a black screen doesn't do much for displaying info