The Open System Driver Interface (OSDI) package included with DP4 provides an application program interface as C code that you can modify to handle devices. You can add the commands for controlling your own devices to this code. The device driver code is loaded into memory, and is executed whenever an application sends data to an output device, or receives data from an input device.
The ability to integrate devices is very important in an environment where specialised devices are used. For example, a POS terminal may use several devices. The input devices might include the keyboard, bar code reader, and magnetic stripe reader. The output devices could include an operator display, customer display and a receipt printer.
The OSDI gives you the means to access a range of devices from an application, in as flexible a manner as possible.
You can find out more in the following pages: