JULY 28 - AUGUST 1, 2008
In this week, we went back to class discussion because last week we had our cooking and movie viewing. Our topic was all about the types of computers. We then defined computer as a device that uses digital technology to process and manipulate information. The types of computers are Microcomputers, Workstation, Minicomputers, Mainframe Computers, Supercomputers and Wearable Computers. The term microcomputer is generally synonymous with personal computer (PC), or a computer that depends on a microprocessor. A personal computer is a small, relatively inexpensive computer designed for an individual user. A portable computer is a computer that is designed to be moved from one place to another (in other words, it is a computer that is portable). A workstation is a desktop computer that has a more powerful processor, additional memory and enhanced capabilities for performing a special group of task, such as 3D Graphics or game development. Midsized computer. In size and power, minicomputers lie between workstations and mainframes. In the past decade, the distinction between large minicomputers and small mainframes has blurred, however, as has the distinction between small minicomputers and workstations. But in general, a minicomputer is a multiprocessing system capable of supporting from 4 to about 200 users simultaneously. Mainframe computers is a very large and expensive computer capable of supporting hundreds, or even thousands, of users simultaneously. In the hierarchy that starts with a simple microprocessor (in watches, for example) at the bottom and moves to supercomputers at the top, mainframes are just below supercomputers. The fastest type of computer. Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations. The latest trend in computing is wearable computers. Essentially, common computer applications (e-mail, database, multimedia, calendar/scheduler) are integrated into watches, cell phones, visors and even clothing!
3 FUNDAMENTAL ELEMENTS OF A COMPUTER
System Unit
Output Devices
Input Devices
The system unit acts like the center or core, processing the data and information it receives from input devices. Output devices like printers receive the system unit’s processed information
The System case
The system case is a plastic and metal box that houses components such as the motherboard, disk drives and power supply unit.
System Case Types
There are two basic types of system case: desktop and tower.
Desktop case: is designed to sit horizontally on a surface, so that it is wider than it is long. These are usually used for office or home PCs. 2 basic sizes: standard and slimline.
Tower case: is designed to sit vertically on a surface, so that it is higher than it is wide. 3 basic sizes: full, midi and mini.
Full-tower cases: are usually used for PC servers.
Midi-tower cases: are used for higher-end user PCs.
Mini-tower cases: are usually for office or home PCs.
Parts of the Case
Cover: the case has a cover which is removed by either undoing the screws at the back, or pressing together clips that release it.
Front Panel: provides access to the floppy and CD, a power on/off switch, a reset switch, and LEDs (light Emitting Diodes) to indicate drive operation.
Parts of front panel cover: CD-R and CD-RW drives, removable hard disk, 3.5 floppy disk,3.5 drive bays, LEDs, Reset switch, Power on/off switch.
THE MOTHERBOARD
The motherboard is the largest board of the computer system. The motherboard contains the CPU, BIOS, memory, mass storage interfaces, serial and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, and disk drive.
Chipset: chips that reside on the motherboard.
The mother board battery: is used to preserve the computer’s clock’s time and your BIOS settings while the computer is turned off.
THE CENTRAL PROCESSING UNIT-CPU
Is the device that interprets and executes instructions.
Today’s single-chip central processing units, called microprocessors, make personal computers and workstations possible.
It has the ability to fetch, decode, and execute instructions and transfer information to and from other resources over the computer’s main data-transfer path, the bus.
It functions as the brain of a computer
CLOCK
The system clock synchronizes the operation of all parts of the PC.
It consists of a clock generator that sets up a timing signal, and clock multipliers.
MEMORY
2 fundamental types:
main memory (RAM)
secondary memory (Floppy disk, USB)
MAIN MEMORY
Very closely connected to the processor.
The contents are quickly and easily changed.
Holds the programs and data that the processor is actively working with.
Interacts with the processor millions of times per second.
Most computers available today have memory capacities of 64Mb to 256Mb.
When programs and data become active, they are copied from secondary memory into main memory where the processor can interact with them.
Main memory sometimes called: RAM
RAM (Random Access Memory), random means that the memory cells can be accessed in any order.
RANDOM ACCESS MEMORY (RAM)
It means the computer can store, retrieve, alter or delete any items held in the RAM’s at random.
It is a semiconductor-based memory that can read and written.
Main memory is build from small circuit boards called MEMORY MODULES.
Still the current standard in system memory, usually of SDRAM (synchronous RAM) type.
DIMM chips are usually distributed in 64MB, 128MB or 256 MB on a single chip.
DIMMs (dual inline memory module) have two access pathways, they do not need to be fitted in pairs as they can be written to and read at the same time.
ROM BIOS
The BIOS (basic input output system) is a ROM (read only memory) chips that provides:
The industry standard program code that operates the fundamental components of the PC (for example, VDU, keyboard, printer port) and ensures that the design of each manufacturer’s motherboard is PC-compatible.
The routines that allow the setup configuration of a PC (stored in the CMOS RAM) to be viewed and edited.
The power-on self-test (POST) diagnostic tests for the PC
BIOS chip cannot be swapped between different motherboards.
The BIOS is often known as firmware as it consists of both the physical chip (hardware) and the programs coded into it (software).
The ROM BIOS is normally a DIP chip that can be identified by a label on the chip.
CMOS RAM
CMOS RAM stores the configuration of the PC.
CMOS stands for Complimentary Metal-Oxide Semiconductors, which describes the manufacturing process used to make RAM chip.
The CMOS battery is either a NICard, lithium or alkaline cell
SECONDARY MEMORY
Connected to main memory through the bus and a controller
The contents are easily changed, but this is very slow compared to main memory
Used for long-term storage of programs and data
The processor only occasionally interacts with secondary memory
Common secondary storage devices are the floppy disk and hard disks and compact disks or CD
It is as thin and flimsy as a sheet of paper but is protected by the sturdy, square jacket that encases it.
Since the rust is made of iron, which can be magnetized, the disks stores magnetic signals.
The pattern of magnetic signals is a code representing your data
3 Standard sizes:
8-inch is called a largefloppy
5.25-inch is called a minifloppy
3.5-inch is called a microfloppy
5.25-inch floppies were invented by Shugart Associates
3.35-inch floppies were invented by Sony.
The typical 3.5 floppy drive holds 1.44 MB.
Drive
Zip, the most popular super-capacity floppy disks is the Zip disk.
It holds 100M, which is 70 times as much as 1.44M floppy
HARD DISK
Might have a storage capacity of 40 gigabytes. This is about 300 times the amount of storage in main memory (assuming 128 megabytes of main memory)
Hard Drives are usually designated as Drive C
Hard disks are better than floppy disks in three ways:
Hard disks are sturdier than floppies
Hard disks are hard and firm; they don’t flop or jiggle. They’re more reliable than floppies
Hard drives hold more info. Than floppy drives.
The typical hard drive holds 40 gigabytes.
The typical floppy disk rotates between 5 and 10 times per second.
The typical floppy disk rotates between 5-10 times/second. The typical hard disk rotates between 90-167 times/second.
The hard disk is non-removable
CD-ROMs
CD that holds music is called a music CD
A CD that holds computer data instead is called a computer CD
The standard CD-ROM disks has a diameter of 12 centimeters and holds 650 megabytes.
The CD can hold 99 tracks, totaling an hour of music or 650 Mb.
CD-RW
CD-rewritable drive, which can write onto a blank CD-RW disk and then edit what you wrote.
DVD
1997, the electronic industry selling an improved kind of CD, called a Digital Versatile Disk (DVD)
Holds 2-hour movie (including the video and sound)
Movie Lovers call it a Digital Video Disk
VIDEO CARD
A board that pugs into a personal computer to give it display capabilities
Graphics Accelerator: adapters graphics coprocessor for performing graphics calculations
Video Card are also called video adapter, video board , video display board, graphics card and graphics
UNDERSTANDING VIDEO GRAPHICS
The video/graphics card converts digital data into signals that can be sent across a connector to you monitor, which interprets the signal into an image on screen.
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