The velleman k8055n interface board has 5 digital input channels and 8 output channels as well as 2 analogue inputs and 2 outputs with an 8 bit resolution these can be expanded further by connecting up to 4 cards to the usb ports on your pc all communication programs are saved in a dynamic link library dll k8055ddll you can write customised windows 98 se 2000 me xp applications in delphi visual basic c builder and any other 32 bit windows auxiliary program for applications support