Computer System and Hardware Components Chapter II IT 105 Prepared by: [email_address]
A computer system consists of
The physical equipment such as case, storage drives, keyboards, monitors, cables, speakers and printers.
Includes the operating system and programs.
The operating system instructs the computer how to operate.
These operations may include identifying, accessing and processing information.
Contains the framework to support a computer’s internal components while providing an enclosure for added protection.
The size and layout of a case is called a form factor . (e.g. desktop (slim line or full sized) and tower (mini or full sized)
Computer cases may also called as computer chassis, cabinet, tower, box and housing .
Factors to consider when choosing a case:
The size of the motherboard
The number of external or internal drive locations, called bays
When choosing a computer case, consider the ff:
There are two main case models, for desktop PCs and for tower computers.
The type of motherboard determines the type of case to be used.
The size and shape must match exactly.
If a computer has many components, it needs more room for airflow to keep the system cool.
The design of the desktop case may limit the number and size of the components that can be added.
Match the power rating and connection type of the power supply to the type of motherboard.
Some people don’t care how the case looks, others do.
LED indicators that are mounted on the front of the case can tell you if the system is receiving power, when the hard drive is being used, and when the computer is on standby or sleeping.
All cases have a vent on the power supply, and some have another vent on the back to help draw air into or out of the system.
Converts alternating-current (AC) power coming from a wall outlet into direct-current (DC) power, which is a lower voltage.
DC power is required for all the components inside the computer.
ATX- more advanced features than AT
ATXv12- add power support for the motherboard by adding another 4-pin power connector.
Most connectors today are keyed connector.
Keyed connectors are designed to be inserted in only one direction.
Power Color Codes
Power Supply Ground: Used to complete circuits with other voltages BLACK 0V ISA bus cards and early PROMS WHITE -5V Motherboard, Baby AT and earlier CPUs, and many motherboard components RED +5V Most newer CPUs, some types of system memory and AGP video slots ORANGE +3.3V Some types of serial port circuits and early Programmable Read Only Memory (PROM) BLUE -12V Disk drive motors, fans, cooling devices, and system bus slots YELLOW +12V ATXv12 Power Supply ATX Power Supply AT Power Supply Use Wire Color Voltage
A keyed connector used to connect to an optical drive or hard drive
A keyed connector used to connect to a floppy drive
It is smaller than Molex
20-pin or 24-pin slotted connector
It used to connect to the motherboard
24-pin has two rows of 12 pins each
20-pin has two rows of 10 pins each
Four-pin-to-eight-pin auxiliary power connector
It has two rows to four pins and supplies power to all areas of the motherboard.
It is the main printed circuit boards.
It contains the buses, or electrical pathways.
These buses allow data to travel between the various components that comprise a computer.
Also known as system board, backplane, or main board
Motherboard accommodates the CPU, RAM, expansion slots, heat sink/fan assembly, BIOS chip, chip set, and the embedded wires.
Sockets, internal and external connectors and various ports are also placed on the mother board.
Various form factors:
AT- Advanced Technology
ATX- Advanced Technology Extended
LPX- Low-Profile Extended
NLX- New Low-Profile Extended
BTX- Balanced Technology Extended
Composed of various integrated circuits attached to the motherboard that control how system hardware interacts with the CPU and motherboard.
It allows the CPU to communicate and interact with computer’s other components and to exchange data with system memory, hard disk drives, video cards and other output devices.
It establishes how much memory can be added to motherboard.
It also determines the type of connectors on the motherboard.
Two distinct components
Controls the access to RAM, video card and the speed at which the CPU can communicate with them
Allows the CPU to communicate with the hard drives, sound card, USB ports and other I/O devices.
CPU (Central Processing Unit)
It is considered the computer’s brain.
Sometimes called the processor.
It comes in different form factors, each style requiring a particular slot or socket on the motherboard.
Common CPU manufacturers include Intel and AMD.
Central Processing Unit
CPU socket or slot
It is the connector that is the interface between the motherboard and the processor.
PGA (pin grid array)- most CPU sockets and processors built today
ZIF (zero insertion force)- the amount of force needed to install the CPU.
Slot-based processors are cartridge-shaped and fit into a slot that looks similar to an expansion slot.
While the CPU is executing one step of the program, the remaining instructions and data are stored nearby in a special memory called cache .
Central Processing Unit
Two major CPU architectures
RISC (reduced instruction set computer)
Architectures use a relatively small set of instructions and RISC chips are designed to execute these instructions very rapidly.
CISC (complex instruction set computer)
Architectures use a broad set of instructions, resulting in fewer steps of operation.
The CPU has multiple pieces of code being executed simultaneously on each pipeline.
A CPU’s speed is rated in cycles per second
Speed (MHZ, GHz)
The amount of data that a CPU can process at one time depends on the size of the processor bus (CPU bus or FSB (front-side bus)).
The wider the processor data bus, the more powerful the processor.
Current processors have a 32-bit or 64-bit processor data bus.
One core inside a single CPU chip that handles all the processing capability.
Two cores inside a single CPU chip, in which both cores can process information at the same time
It is installed in the computer case to make the cooling process more efficient.
A fan on top of the heat sink moves away the heat from the CPU.
Graphics Card Cooling System
Fans are dedicated to cooling the graphics-processing unit (GPU).
ROM (Read-only Memory)
Chips that contain instructions that the CPU can access directly.
Stores basic instructions for booting the computer and loading the operation system.
The contents cannot be erased, changed, or rewritten by normal means.
ROM types includes:
PROM (Programmable read-only memory)
Cannot be erased or rewritten
EPROM (Erasable programmable read-only memory)
Can be erased with exposure to UV light.
EEPROM (Electrical EPROM)
Also called as flash ROMs.
It can be erased and rewritten without removing the chip from the computer
RAM (Random Access Memory)
It is the temporary storage for data and programs that are being accessed by the CPU.
It is a volatile memory.
Types of RAM are as follows.
DRAM (Dynamic RAM)
A memory chip that is used as main memory.
SRAM (Static RAM)
A memory chip that is used as cache memory.
FPM DRAM (Fast Page Mode DRAM)
A memory that supports paging.
Paging enables faster access to the data than regular DRAM.
EDO (Extended Data Out) RAM
A memory that overlaps consecutive data accesses. This speeds up the access time to retrieve data from memory
Synchronous DRAM (SDRAM)
A DRAM that operates in synchronization with the memory bus.
Double Data Rate ( DDR) SDRAM
A memory that transfers data twice as fast as SDRAM.
A memory that is faster than DDR-SDRAM.
It decreases noise and crosstalk between signal wires.
RAMBus DRAM (RDRAM)
A memory chip that was developed at very high rates of speed.
DIP (Dual Inline Package)
Is an individual memory chip. A DIP had dual rows of pins used to attached it on the mother board.
SIMM (Single Inline Memory Module)
A small circuit board that holds several memory chips. SIMM have 30-pin and 72-pin configurations.
DIMM (Dual Inline Memory Module)
A small circuit board that holds SDRAM (168 pins), DDR (184-pins), and DDR2 (240-pins).
SRAM is used as cache memory to store the most frequently used data.
SRAM gives processor faster access to the data than retrieving it from slower DRAM or main memory.
Types of cache memory
L1 is internal cache integrated into the CPU.
L2 is external cache originally mounted on the motherboard near the CPU.
L3 is used on some high-end workstations and server CPUs.
Nonparity does not check for errors in memory.
Parity contains 8 bits for data and 1 bit for error checking. The error-checking bit is called a parity bit.
Error Correction Code (ECC) can defeat multiple bit errors in memory and correct single bit errors in memory.
Adapter cards increase a computer’s functionality by adding controllers for specific devices or by replacing malfunctioning ports.
NIC connects a computer to network using a network cable.
Wireless NIC connects a computer to a network using radio frequencies.
Provides audio compatibility.
Provides graphic capability.
Connects a computer to the internet using phone line.
Connects SCSI devices such as hard drives or tape drives to a computer.
Connects multiple hard drives to a computer to provide redundancy and improve performance.
To connect peripheral devices:
ISA (Industry Standard Architecture)
Is an 8-bit or 16-bit expansion slots. This is older technology and is seldom used.
EISA (Extended ISA)
It is a 32-bit expansion slot and is seldom used.
MCA (Microchannel Architecture)
Is an IBM proprietary 32-bit expansion slot.
AGP (Advanced Graphics Port)
Is 32-bit expansion slot. It is designed for video adapters.
PCI (Peripheral Component Interconnect)
Is a 32-bit or 64-bit expansion slot.
Is a serial bus expansion slot.
It is backward-compatible with PCI slots.
A storage drive reads or write information to magnetic or optical storage media.
Storage drives can be installed inside the computer case such as hard drive.
For portability, some storage drives can connect to the computer using USB port, FireWire port or SCSI port.
Types of storage drives:
Floppy Drives (A: drive)
Is a storage device that uses removable 3.5 inch floppy disks.
This can store 720 KB or 1.44 MB of data.
One of the oldest technology.
Hard Drives (C: drive/D: drive)
Is a magnetic storage device that is installed inside the computer.
Is used as permanent storage for data.
Capacity-GB and speed rpm (revolutions per minute)
Is a storage device that uses lasers to read data on the optical media.
Compact Disc (CD)
Digital Versatile Disc (DVD)
CD and DVD media can be prerecorded (read-only), recordable (write once), rerecordable (read and write multiple times)
Other types of optical media:
Legend: PR-Prerecorded, RO- Recorded once, E- Erased, RR-Rerecorded, R-recorded
Also known as thumb drive
Is a removable storage device that connects to a USB port
Storage capacity is up to 16 GB
Is a connection to a remote computer’s storage for access to files, directories, and applications.
Types of Drive Interfaces
Integrated Drive Electronic (IDE )
Also called Advanced Technology Attachment (ATA) , an earlier drive controller interface that connects computers and hard disk drives.
It has 40-pin connector.
Enhanced Integrated Drive Electronics (EIDE)
Also called ATA-2, is an updated version of the IDE drive controller interface.
Parallel ATA (PATA)
Refers to the parallel version of the ATA drive controller interface.
Serial ATA (SATA)
Refers to the serial version of the ATA drive controller interface.
Uses 7-pin connector .
Small Computer System Interface (SCSI)
A drive controller interface that can connect up to 15 drives. It uses a 5-pin, 68-pin, or 80-pin connector.
Data cables connect drives to the drive controller, which is located on an adapter card or the motherboard.
Types of data cables:
Floppy disk drive (FDD) data cable
Has up to two 34-pin drive connectors and one 34-pin connector for the drive controller.
PATA (IDE) data cable
Has 40 conductors, up to two 40-pin connectors and 40-pin connector for the drive controller.
PATA (EIDE) data cable
Has 80 conductors, up to two 40-pin connectors for drives and one 40-pin connector for drive controller.
SATA data cable
Has seven conductors, one keyed connector for the drive and one keyed connector for the drive controller
SCSI data cable
A narrow SCSI data cable has 50 conductors, up to seven 50 –pin connector, and one 50 – pin connector for host adapters
A wide SCSI data cable has 68 conductors, up to 15 68 –pin connector, and one 68 – pin connector for host adapters
An Alt-4 SCSI data cable has 80 conductors, up to 15 80 –pin connector, and one 80 – pin connector for host adapters
Ports and Cables
Can be either DB-9, or DB-25 male connector
To connect a serial device, such as modem or printer, serial cable must be used.
A serial cable has a maximum length of 50 feet (15.2 m)
Is standard interface that connects peripheral devices to a computer.
A single USB port in a computer can support up to 127 separate devices with the use of multiple USB hubs.
USB 1.1 -12 Mbps
USB 2.0 – 480 Mbps
Is a high-speed, hot-swappable interface that connects peripheral devices to a computer.
A single FireWire port in a computer can support up to 63 devices.
Ports and Cables
Is a standard Type A DB-25 female connector.
To connect a parallel device, such as printers, a parallel cable must be used.
A parallel cable has a maximum length of 15 feet.
If a single SCSI device is connected to SCSI port, the cable can be up to 80 feet in length.
Can support up to 15 devices.
Also called an RJ-45 port, connects a computer to a network
The connection speed depends on the type of network port
Standard Ethernet can transmit up to 10 Mbps, Fast Ethernet can transmit up to 100 Mbps, and Gigabit Ethernet can transmit up to1000 Mbps
Ports and Cables
Connects a keyboard or mouse to a computer
Is a six-pin mini DIN female connector
Connects audio devices to the computer
Common audio ports
Line In –connect external source such as stereo
Microphone In –connects to a microphone
Line Out –connects to speakers or headphones
Auxiliary In –an additional line in
Gameport/MIDI –connects to a joystick or MIDI-interfaced device
Ports and Cables
Connects a monitor cable to a computer
VGA (Video Graphics Array)
Has three-row 15-pin female connector
DVI (Digital Visual Interface)
Has a 24-pin female connector or 29-pin female connector
HDMI (High-Definition Multimedia Interface)
Has 19-pin connector
Provides both analog and digital signals
Has 4-pin connector and provides analog signals
Has three shielded cables (red, green, and blue) with RCS jacks and provides analog signals
Is used to enter data or instructions into a computer
Mouse and Keyboard
Digital Camera and Digital Video Camera
Biometric Authentication Device
Is used to present information to the user from a computer
CRT (cathode ray tube)
LCD (liquid crystal display)
DLP (digital light processing)
Printers, scanners, and fax machines
Speakers and headphones
Project #1 (individual or by pair)
Choose your own partner. Create a portfolio that compiles all the images of all given hardware components and sub-components.
Indicate their names and functions.
Categorize them for better readable output.
Use your own creativity, formal or informal.
Deadline is before or on the preliminary exam day.