I2C LPT Interface Test Utility - InpOut32.DLL

When I started upgrading my Windows 95/98 systems to Windows NT/2000 and later on to Windows XP, Vista x64 and now Windows 7 x64, I ran into the problem that suddenly my I2C interfaces via the parallel port (LPT) did not work anymore. As of Windows NT / 2000 it was no longer allowed by the OS to address hardware ports immediately. Fortunately this problem was recognized as well by other people and all kind of alternative ways to bypass this unpleasant part of Windows came up. One of the alternatives is the InpOu32.DLL. This DLL makes it possible to address the hardware ports via the normal Inp and OUT commands in your software. For more information about the InpOut32.dll. visit the website of http://www.logix4u.net/inpout32.htm.

I have used the InpOut32.DLL to develop a Visual Basic module, I2C_InpOut32.bas, which makes it possible to send and receive I2C commands to / from the parallel port. The I2C_InpOut32.bas module works with the I2C interface published in the Elektor / Elektuur of October 2000. I have written a small application, from which you can test several I2C devices via the parallel port by using the InpOut32.DLL. The I2C interface electric diagram can be found on this website as well. It is an easy to build interface. Go to the Schematic part to view the electric schematic and to download the the software.   

New Computers, No LPT onboard
Most of all new computers or mainboards does not have standard a LPT on board. When you  want to have a LPT, you have to install a LPT PCI card to get one.  Although these LPT PCI cards claims that they support legacy LPT addresses, like $378, you will foind out that your programs that uses LPT1 on $378 still doe snot work. So that is also the case with the I2C LPT Test Utility. Therefore I added the option to enter a LPT PCI address.

New Release 3.0.1!!!
Release 2.0.0 has become available. See the Screenshot of the application!!
I2CInpOut32.exe can be used with all Windows versions!!!

Release History


Recompiled to work with Vista and Windows 7 x64.
Added LPTx option to be able to address LPT PCI cards.



Added PCF8591 AD/DA converter and SAA1064 4-Digits display driver devices.


 Initial release of I2C InpOut32.DLL Utility.




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