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About parallel port's bi-directional feature.

I am now developing a peripheral that uses the parallel port to read data from it and store in the PC. As you know, a standard parallel port only allows data out through the data register. I also heard that there is a bi-directional mode that allows data in & out through the data register, but not all cards support it. Is there any simple ways for me to acheive this task? Or, if I should use the bi-directional mode, how can I know that my PC supports this mode and what config. should I make to use this mode?
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Peggie
Asked:
Peggie
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PeggieAuthor Commented:
Edited text of question.
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RudolfFraDKCommented:
You find a really interesting Paralell port article on ths adress:
http://www.hut.fi/Misc/Electronics/circuits/lptpower.html
A cutout from this text:
"Standards called EPP (Enhanced Parallel Port) and ECP (Extended Capabilities Port) brought many enhancements. The most important one is the possibility of bi-directional communication over the data pins D0-D7, due to modified hardware design of these pins."
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PeggieAuthor Commented:
Could you please tell me whether all the PCs support the ECP & EPP mode and how can I make use of these modes?
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Z_BeeblebroxCommented:
Hi,

Almost all computers support this, anything 486 or higher should definately support this. To enable it, there is a setting somewhere in your BIOS, accessed when booting up the computer by pressing INS, or DEL, or F1 and then changing your parallel or LPT1 settings. Where in your bios it is depends on your computer. When you find it, just toggle the settings until it says something like bi-directional or EPP or ECP. I don't want to look it up in my BIOS right now, but if you can't find it I will take a look and tell you exactly what it is likely to be called. Mostly likely though, it is already enabled by default since most new printers these days use it so that they can communicate with your computer.

Zaphod.
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PeggieAuthor Commented:
Thank you for your kindness help. I have a few more questions to ask.
1. Is it that the printer card will generate all the handshake signals instead of the programs when using EPP mode?
2. If my application requires me to take over the control of the handshakes, how can I achieve?
3. How can I utilize the read operation?
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