Windows 95 pen device support consists of a pen device driver and a pen calibration application that extends the Windows 95 control panel.
The pen device generates hardware interrupts at a rate of approximately 100 interrupts per second. At each hardware interrupt, the pen Unidriver collects pen data from the device and provides the data to Windows in the form of a pen packet. Generally, each interrupt produces a packet, which is the elemental form of raw pen data. Each packet contains the current pen coordinates, the pen state (up, down, in transition, etc.), a time stamp, and optional OEM information. Collectively, pen packets provide a digitized history of the pen's movements.