Keyboard working functions

How do a keyboard work

A keyboard works by when you press a letter/button on a keyboard the keyboard will scan the logic in the keyboard the keyboard will send a key code to the keyboard controller to be stored in the keyboard register.

The CPU will retrieve the key from the keyboard it will send an instruction from the keyboard controller instruction set to the KBD controller which will place it on the data bus.

BIOS is the firmware that comes with the motherboard that stored in the BIOS chip is different than the CMOS chip.

Two types of hardware the BIOS has to deal with are: Non changeable hardware such as the keyboards and speaker and changeable hardware such as the memory and disk drivers.

Specific details about the changeable hardware is stored in CMOS.

Saving configuration from the UEFI writes information to the CMOS.

System will notify you if info in CMOS does not match what it finds in the system.

CMOS is volatile memory. It requires power that is supplied from the battery on the motherboard.

System manufacturers provide a ROM base system setup utility run once at system power on.

CMOS (Complementary metal oxide semiconductor).

A device driver is a piece of software that sits between the OS and a piece of hardware.

It implements a set of standard functions so the OS or application through the OS can communicate with the piece of hardware.

The four basic units of electricity

Term

Measurement

Function

Why

Voltage (V)

Volts

A measure of work required to move a

charge from one location to another

Power supply outputs are measured in volts.

Resistance (R)

Ohms

The opposition or restriction to a flow

of current.


Current (l)

Amperes

A measure of the amount of electrons

per second moving through a circuit.

Power supplies deliver different amperages for each voltage.

Power (P)

Watts

Voltage * current

A computer power supply is rated in Watts.

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