Parallel Port

k_oz used Ask the Experts™
I need to send and receive data via the
Parallel Port. Does any one have
some tips???


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You dont say which version of Delphi, but I have used the venerable PC's printer port for general purpose IO from Delphi 1 for some time.  Not tried it in any of the 32 bit versions though!...

In general, use the "Port" function to output and input data.  I'd recomend you do a web search to find any of a number of documents about the structure of the printer port, as seen by the CPU.  Check some of the Ham radio sites for links... and for example.  You may need to follow links to users sites first though....

Other people have sugested opening it as a channel in the normal way before messing with it.  But I've found in the past that can generate some unexpected interupts, with all the stability issues that involves.

Stick to programed IO methods and you cant go too far wrong, but be aware, that even this "simple" interface can throw a few suprises to the unwary!

Or, build your hardware to "fake" the presence of a printer, and then throw data at it in the "normal" way..

I don't know how to put attachements to this forum, if anyone knows, I can post some code that I know works...

Best Regards...

de G8KBV.

I use smallport component. It's really what you need ;)

There is also ZLPortIo wery similar, but don't know why I didn't like it.

You get it at:

Hope it helps.


I would recommend SmallPort, it works fine, even in WinXP, which I am using.

If you need help using it just give me a yell.

I will send you some sample progs if you like.


HushPe =)
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