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still reading from the printer

Posted on 1998-02-09
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I asked a question earlier about how to axcess the parrallel port of the computer when programing in Visual C++.  The answer I got back was to use it as I would a normal data file.  The problem I am having is that I am not sure how to treat the data I will be getting from the parallel port.  I am going to be connecting an encoder to the port.  This is going to give me either a high or low signal on the pins of the parallel port.  When I try to read this in how is it going to be represented?  Cam I axcess this information bit by bit from the port?  Would each bit be corrisponding to a particular pin?  Can I read off of some of the pins and write to others?  I am having a hard time understanding the big picture here so any help with a general overview would be helpful, but a detailed answer with examples would be perfered.
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Question by:jcoleman012698
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by:nietod
ID: 1181622
I believe

If you acces the port as a file, you can read bytes (characters) from the file.  Each character represents the 8 data lines put together.  You cannot access the control lines in this way.

If there is no data to read, the read operation indicates that you've reached the end of file.
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q2guo earned 100 total points
ID: 1181623
Go to my homepage at http://www.csclub.uwaterloo.ca/u/q2guo/parallel.txt
for a mini faq on accessing the parallel port.  The faq helped
me a lot.  It contains some C source codes.


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