Velleman Compact USB Interface Card Module VM110N
This is for home experimenters who fancy developing some station automation . The VM110N interface board has 5 digital input channels and 8 digital output channels. In addition, there are two analogue inputs and two analogue outputs with 8 bit resolution. The number of inputs/outputs can be further expanded by connecting more (up to a maximum of four) cards to the PC's USB connectors. All communication routines are contained in a downloadable Dynamic Link Library (DLL) K8055D.DLL. You may write custom Windows applications in Delphi, Visual Basic, C++ Builder or any other 32-bit Windows application development tool that supports calls to a DLL. Source code for Visual Basic , Visual C++, Visual C#, Excel, Delphi and Borland C++ Builder is downloadable. See product information here.
Asking £15 incl. UK mainland P&P.