Hi to all, Based on what I understood PS2 keyboard uses bi-directional communication. I am not sure about the mouse does it work similar way "bi-directional" or mouse is just output device? my main question is Can I use PIC's hardware SPI interface for keyboard or mouse. I like PIC18F parts. any info will appreciate. thank you Andre -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist