Essential Computer Expansion Cards and Peripherals

1. Expansion Cards

Utility

Expansion cards add new features or improve existing ones in a computer. They facilitate communication between internal and external peripheral devices and the system bus.

Disk Controller Card

Disk controller cards, once used to manage hard disks, CD-ROMs, DVDs, and floppy drives, are now integrated into the motherboard.

Video Card

The video card is crucial for displaying text, images, and graphics on the monitor.

Components

• Video Processor: Receives, processes, and stores information in video memory, transmitting it to the monitor via the VGA connector.
• Memory Chips: Hold information needed to display pixels on the screen.
• AGP: Allows the card to be inserted into the AGP slot.
• Port for the Monitor: Connects the card to the monitor.
• RAMDAC Chip: Reads data from video memory, converts it to analog signals, and sends it to the monitor for display.

Sound Card

Sound cards enable computers to record and play sounds from internal or external sources. They convert analog sounds (e.g., from a microphone) into digital format.

Connectors

• Expansion Bus: Connects the card to the motherboard (ISA or PCI slots).
• Audio CD: Plays music CDs through the sound card (requires CD-ROM connection).
• Line In: Connects a CD player or stereo system to the sound card.
• Microphone In: Connects a microphone for recording sounds.
• Speaker Out (SPK): Connects to speakers or headphones.
• Joystick: Allows connection of a joystick for games.

Parallel Ports

Function

Parallel ports, like serial ports, are named for how they send and receive information.

Transmission

Information is sent in eight-bit parallel instead of bit by bit.

Operating System Name

LPT

Connectors

1. DB25 (originally DE-25) is a 25-pin analog D-Subminiature (D-Sub or Sub-D) connector.

Standards

1. Standard Parallel Port (SPP): Defines a parallel port for unidirectional data transfer (computer to device).
2. Enhanced Parallel Port (EPP): Defines a parallel port for bidirectional data transfer (computer to device and device to computer), but not simultaneously.
3. Enhanced Capabilities Port (ECP): Allows simultaneous bidirectional communication between the device and the computer.

2. Peripheral Devices

Peripheral devices send and receive data, facilitating communication between the computer and the external world. They are considered integral parts of a computer system.

• a. Input Peripherals: Used to introduce data into the computer (e.g., keyboard, mouse).
• b. Output Peripherals: Display the results of a process (e.g., printer, monitor).
• c. Storage Peripherals: Hold information for processing or transfer to the computer's main memory (e.g., hard disk).
• d. Communication Peripherals: Enable communication with remote devices (e.g., network cards, modems).