Transcription: How does the computer know which key has been pressed? The current flows from the key to a chip in the keyboard called a microprocessor. This processor matches the keystroke with the table of scan codes. These numbers are used to identify letters in the alphabet. The microprocessor passes this new code number onto a sort of high-tech waiting room in your RAM, that is your random access memory. RAM holds your letter until the PC is ready to use it. At the same time, The keyboard's microprocessor sends a signal to another device, the interrupt controller. It tells your PC to stop what it's doing ...
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