Getting Started NOTES

Hardware and Software are the two basic parts of a computer system.

HARDWARE

            any part of a computer system that you can see or touch.

PERIPHERAL

            any piece of hardware attached to a computer, such as a printer or keyboard.

SOFTWARE

            a set of electronic instructions that tell the computer what to do.  You cannot see       

           or touch software, although you can see the packaging it comes in.

TYPES OF SOFTWARE

            application software- let you accomplish specific tasks.  You can write letters,

            analyze numbers, sort files, manage finances, draw pictures and even play games.

            operating system software- sets the rules for how computer hardware and 

            application software work together.

A Computer collects processes, outputs and stores information.

INPUT

            devices provide a way of communicating with a computer. These devices let you 

            enter information and issue commands.

OUTPUT

            device lets a computer communicate with you. These devices display information 

            on a screen, create printed copies of information or generate sound. Monitor, 

            printer, and a set of speakers.

PROCESS

            The central processing unit (CPU) is the main chip in a computer. It processes 

            instructions, performs calculations, and manages the flow of information through 

            a computer system. The CPU communicates with input, output, and storage 

           devices to perform tasks.

STORAGE

            device holds information. The computer uses information stored on these devices 

            to perform tasks.

Basic Computer Parts

TYPES OF COMPUTER CASES

            case contains all the major components of a computer system

                        DESKTOP CASE- usually sits on a desk, under a moniter

                        TOWER CASE- usually sits on the floor. Provides more

                                    desk space, but makes it difficult to insert disks.

POWER SUPPLY

            changes normal household electricity into electricity that a computer can use.

HARD DRIVE

            the primary device that computers use to  store data

MOTHERBOARD

            main circuit board of a computer.  All electrical components plug into the 

            motherboard

CPU

            main chip in a computer. It processes the instructions, performs calculations and 

            manages the flow if information through the computer.

RANDOM ACCESS MEMORY (RAM)

            temporarily stores data inside a computer. This data disappears when you turn off 

           the computer.

BUS

            electronic pathway in a computer that carries information between devices.

BUS SPEED

            the higher the speed, the faster data travels along the bus. Speed is measured in

            megahertz (MHz)

EXPANSION CARD

            small circuit board that connects to the motherboard to add more quality

            to video, sound, modem

                                                           MEMORY

            the amount of memory, or memory size, in a computer determines the number of 

            programs you can run at once. Memory size also determines how fast your  

            programs will operate.

RANDOM ACCESS MEMORY (RAM)

            temporarily stores data inside a computer. This data disappears when you turn off 

           the computer.

READ ONLY MEMORY (ROM) permanent internal memory containing data or 

             operating instructions that can be read but not altered by the user.

MEASURING MEMORY

            bytes are used to measure memory and the capacity of storage devices such as 

            floppy disks, hard drives, and flash drives.

            BYTE- one character. A character can be a number, letter or symbol.  *a byte 

                         consists of 8 bits*

            MEGABYTE (MB) approximately one million characters

            GIGABYTE (GB) approximately one billion characters

TYPES OF MEMORY

            Dynamic RAM (DRAM) is relatively inexpensive and is used for the computer’s 

           main memory. You can improve the performance of a computer by adding more    

           DRAM.

            Video RAM (VRAM) is slightly faster and more expensive than DRAM.

            Video adapters with VRAM are used for high-end applications such as desktop 

            publishing and photo programs. Lower cost video adapters with DRAM are used 

           for routine office tasks.

            Static RAM (SRAM) works at very high speeds and is the most expensive type      

            of  memory. SRAM improves the performance of the CPU by storing data         

            recentlY  used.  This lets the CPU quickly retrieve the data it needs.

CENTRAL PROCESSING UNIT

            CPU (microprocessor)

                        performs millions of calculations every second, each new generation of  

                       CPU is faster and more powerful than the previous generation. The CPU 

                       speed is a major factor in determining how fast a computer operates.

                      The speed of a CPU is measured in megahertz (MHz) which indicates           

                       millions of cycles per second.  The faster the speed the faster the computer            

                      operates.

HARD DRIVE

is the primary device that a computer uses to store information.  If your computer has one hard drive it is called drive C. The hard drive magnetically stores data on a stack of rotating disks called platters.  The platters are made of glass or aluminum. The amount of information a hard drive can store is measured in bytes. The speed that a hard drive finds data is called the average access time. Speed is measured in milliseconds.  The lower the number the faster the hard drive.

DISK CACHE

            part of the computer’s main memory that is set aside to store data recently used

            by the CPU.  When the CPU needs data, it first looks in the disk cache.  The

            disk cache can supple data thousands of times faster than the hard drive.