system unit

COMPUTER SYSTEM UNIT

DEFINITION

The system unit is the box-like case that contains the electronic components of a computer. Many people erroneously refer to this as the CPU. Here you will find devices like the power supply, different drives, the fan, the connectors, and the motherboard. Note that in most cases, the monitor, keyboard, and mouse will not be found inside the system unit layout.

Other names for the system unit include the computer chassis, cabinet, box, tower, enclosure, housing, or simply case.

COMPONENT

MOTHERBOARD

The motherboard is sometimes called the system board or main board. It is the main circuit board of a microcomputer. This component contains the connectors for attaching additional boards. All other parts connect in one way or another to the motherboard.

This part typically contains the CPU, BIOS, memory, mass storage interfaces, serial and parallel ports, expansion slots, and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, mouse, and disk drive.

When you are reading about motherboards, you won't fail to come across the term motherboard form factors, which describes the general shape, the type of case, and the power supply it can use. It also describes the physical organization of the motherboard.

HARD DISK DRIVE

A hard disk drive is a high capacity, non-volatile, magnetic data storage device with a volume (disk) that is usually non-removable.

Data is magnetically read and written on the platter by read/write heads that float on a cushion of air above the platters.

FLOPPY DISK DRIVE

This is a disk drive that can read and write floppy disks, although they are obsolete nowadays.

These drives have been replaced by the USB flash disk drives in modern machines.

POWER SUPPLY UNIT

The power supply unit (PSU) is used to convert AC currents from the main supply to the different DC voltages required by various computer components.

Power supplies are quoted as having a certain power output specified in watts, A standard power supply would typically be able to deliver around 350 watts.

You will need more power from the power supply if your PC has more operating components.

PROCESSOR

A computer engine, its brain. CPU (central processing unit) manages most of computer operations. Processors can be with pins or pin-less. It contains a control unit and a logic unit.

RAM (random access memory)

Primarily memory. It storages all data processed by programs and apps on the computer. There are dynamic and static RAMs.

VIDEO CARD (graphics adapter)

With its help the outputs from a computer are displayed on the screen. Modern video cards support HDMI (high-definition multimedia interface), VGA (video graphics array) and DVI (digital visual interface).