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A question for parallel LCD users

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  • A question for parallel LCD users

    With your LCD connected to the parallel port, is it possibe to sent ASCII characters to the LCD from a DOS batch file?

  • #2
    You should be able to. I used something simmilar when trying out a serial module for a LCD. But I used a copy con com2. What you have should work as well.

    The best way is to just try it. If it works is works. If not well we know it will not.


    • #3
      I would try it if I had my LCD. I just ordered it a few days ago and I am anxiously awaiting it's arrival.


      • #4
        Where did you buy your LCD?


        • #5
          Actually, it doesn't work Most LCDs require not only ASCII text data, but special control signals as well. Simply sending raw ASCII won't make it show up on the character LCD module. First there is an initialization sequence and then each character needs to be clocked into the LCD's internal RAM.

          It wouldn't be hard to write a program to pipe text to it that you could use in a batch file... I have a simple C program for DOS that lets you type characters and have them show up, like a word processor.

          Serial LCDs have all the "brains" needed to convert serial ASCII into control & data signals to talk to the LCD properly, and DOS knows how to send standard serial data, so that is why you can pipe text into a serial LCD so easily.


          Jason Johnson
          Yorba Linda, California

          MPC Phase IV - *** PENDING ***


          • #6
            mpRover: I bought my LCD from It's a 4x20 w/blue-green EL backlight and HD44780 controller.

            jjohnson: where can I get your program (or source code?)


            • #7
              Try here


              This is a prog called LCDPrint that lets you sent a DOS batch file to a parallel port LCD panel.

              Works well.


              • #8
                uhm is an isp..
                Where did you buy your lcd from again?


                • #9
                  If you look near the top of the page I think there is a link to a sale.. They have a lot of LCDs actually. I was confused first myself heh.
                  MP3 Cavalier -
                  MP3 Grand Prix -