Keyboard

83-Key PC /XT keyboards Obsolete keyboard ,is not compatible with new version ofmotherboard.(via a special serial data link). 84-Key AT Keyboard Obsolete keyboard (bi-directional) Enhance 101 –Key keyboard International standards, with 5 pin DIN connector, latest cables with 6-pin mini-DIN connector. 104-Key windows Keyboard Additional key is (WIN Keys & Application key) Ergonomic Keyboard it angling 2 halves main keypad for elbows to rest in natural position Capacitive Key Switching It’s cheap & high reliability, it’s made of 2 plastic plates connected in a switch matrix design to detect change in the capacitance of the circuit. their switch are resistant to key bounce problems.& does not rely on metal contacts therefore it immune to corrosion & dirt Mechanical Key Switch 1. Pure Mechanical Metal contacts ,durable cheap 2. Foam Element mechanical Key switch Have a foam elements with an electrical contact on the bottom, easily to corrosion on the foil conductor & the circuit board & cause key strikes. 3. Rubber Dome Mechanical Key Switch Has carbon button contact 4. Membrane Mechanical Key Switch Normally use in harsh environments example cash registers because it’s difficult to type accurately & quickly it has plastic shell to cover the keys from getting dirt