List of practicals 1. Identify and define various computer components and parts. 2. Describe and different various Motherboard Processors, RAM, Secondary storage devices. 3. Maintenance of computer system. 4. Installing Software on Computer. 1. Computer components and Parts There are many components and parts that work together to make a computer work. Hardware & Software Hardware All of the electronic and mechanical equipment in a computer is called the hardware. Examples include: • Motherboard • Hard disk • RAM • Power supply • Processor • Case • Monitor • Keyboard • Mouse Hardware Physical parts of the computer, including processor and memory chips, input/output devices, tapes, disks, modems, cable, etc. CPU The CPU (Central Processing Unit) is the part of a computer system that is commonly referred to as the "brains" of a computer. The CPU is also known as the processor or microprocessor. The CPU is responsible for executing a sequence of stored instructions called a program. Processor The CPU – The chip or chips that interpret and execute program instructions and manage the functions of input, output, and storage devices. Computer Case Contains the major components of the computer. It helps protect them. Front of the Computer Case Inside the Computer Case Monitor A display screen to provide “output” to the user. It is where you view the information your are working on. Video Card Connects the computer to the monitor. It is a circuit board attached to the motherboard that contains the memory and other circuitry necessary to send information to the monitor for display on screen. Keyboard Used to enter information into the computer and for giving commands. Mouse An input device operated by rolling its ball across a flat surface. The mouse is used to control the on- screen pointer by pointing and clicking, double-clicking, or dragging objects on the screen. Touchpad A pressure-sensitive and motion sensitive device used in place of a mouse. CD Rom Drive The drive that plays CDs and reads data that has been stored on the CD. CD Compact Disk – A type of optical storage device. Floppy Disk Drive A device that holds a removable floppy disk when in use; read/write heads read and write data to the diskette. Hard Disk Magnetic storage device in the computer. RAM Random Access Memory RAM is a computer’s temporary memory, which exists as chips on the motherboard near the CPU. It stores data or programs while they are being used and requires power. Printer An output device that produces a hard copy on paper. It gives information to the user in printed form. Barcode Reader An input device that converts a pattern of printed bars into a number that a computer can read. They are often used by businesses to quickly input price and product information. Scanner A device that allows pictures to be placed into a computer. Microphone Allows the user to record sounds as input to their computer. Speakers Used to generate or reproduce voice, music, and other sounds. Sound Card Connects the speakers and microphone to the computer. Modem The place where the computer is connected to the phone line. Network Card A circuit board that connects the computer to the rest of the network usually using special cables. Software Programs that tell the computer what to do. It provides instructions that the CPU will need to carry out. DOS Disk Operating System This software connects the hardware with the programs you want to run. MS-DOS: Microsoft DOS (Disk Operating System) is a command line user interface. MS-DOS 1.0 was released in 1981 for IBM computers. Windows A family of operating systems developed and produced by Microsoft Corp. It provides a software graphical user interface (GUI) used on IBM and compatible computers. 2. The Motherboard The most important part of a PC is the motherboard. It holds: the processor chip memory chips chips that handle input/output (I/O) the expansion slots for connecting peripherals Some chips are soldered onto the motherboard(permanent), and some are removable (so they can be upgraded). 31 Different types of motherboards: The oldest of the main boards, these motherboards were used in earlier 286/386 or 486 computers. The AT means the board consists of advanced technology(AT) power connectors. There are two power connectors of 6 pin each mounted on the AT motherboards. The AT motherboards were available in the early 80’s. ATX motherboard (Advanced Technology EXtended motherboard) The PC motherboard that superseded the Baby AT design. The ATX layout rotated the CPU and memory 90 degrees, allowing full-length expansions to be plugged into all sockets. The power supply blows air over the CPU rather than pulling air through the chassis. Introduced in 1995, the ATX was the first PC motherboard to not only include I/O support (serial, parallel, mouse, etc.), but to place all the connectors directly on the motherboard. Prior to the ATX, only the keyboard connector was attached to the motherboard. Numerous variations of the ATX were subsequently introduced with both smaller and larger form factors, including the microATX, Mini ATX, FlexATX and Extended ATX. At Motherboard (Advanced Technology motherboard) A motherboard that follows the same design and 12x13" form factor that was in the original IBM PC/AT. It was superseded by the Baby AT. See Baby AT motherboard and PC motherboards. RAM Random Access Memory (RAM). RAM is used to hold programs while they are being executed, and data while it is being processed. RAM is volatile, meaning that information written to RAM will disappear when the computer is turned off. Types of Ram Dynamic RAM: loses its stored information in a very short time (for milli sec.) even when power supply is on. D-RAM’s are cheaper & lower. Similar to a microprocessor chip is an Integrated Circuit (IC) made of millions of transistors and capacitors. In the most common form of computer memory, Dynamic Memory Cell, represents a single bit of data. The capacitor holds the bit of information – a 0 or a 1. The transistor acts as a switch that lets the control circuitry on the memory chip read the capacitor or change its state. A capacitor is like a small bucket that is able to store electrons. To store a 1 in the memory cell, the bucket is filled with electrons. Static Ram Static RAM uses a completely different technology. S-RAM retains stored information only as long as the power supply is on. Static RAM’s are costlier and consume more power. They have higher speed than D- RAMs. They store information in Hip-Hope. In static RAM, a form of flipflop holds each bit of memory. A flip-flop for a memory cell takes four or six transistors along with some wiring, but never has to be refreshed. This makes static RAM significantly faster than dynamic RAM. However, because it has more parts, a static memory cell takes up a lot more space on a chip than a dynamic memory cell. Therefore, you get less memory per chip, and that makes static RAM a lot more expensive. Static RAM is fast and expensive, and dynamic RAM is less expensive and slower. Static RAM is used to create the CPU’s speedsensitive cache, while dynamic RAM forms the larger system RAM space. Secondary storage Device A secondary storage device refers to any non-volatile storage device that is internal or external to the computer. It can be any storage device beyond the primary storage that enables permanent datastorage. A secondary storage device is also known as an auxiliary storage device or external storage. Types of Secondary storage Device Magnetic Tape Hard Disk Floppy Disk Compact Disk/DVD Pen Drive Magnetic Tape • Thin layer of material capable of storing a magnetic signal • Usually contains Iron Oxide • Protected by backing layer called the “Substrate” Examples of Magnetic Media • Some you are probably familiar with: • Cassette tapes • VHS video tape • Computer Tape • 8-track • DAT Hard Disk • Today, most people use Hard Disks for secondary storage • The basic technology used in hard disks is similar to that of magnetic tape • Magnetic material is layered onto a high-precision aluminum disk • The disk head can move to any point on the platter almost instantly compared to tape • With tape, the head touches the tape. With disks, the head never touches the platter • Tape moves at approx 5 cm/s. Disk platters move at up to 7500 cm/s (272 km/h!) Floppy Disks • Floppy disks are similar to hard disks • Because the medium is “floppy”, the disks cannot operate at the same speeds as a hard disk. • Floppy disks are older technology which haven’t received a lot of attention since the late 1980s. • Their capacity hasn’t increased much • Many computers today do not even come with floppy disk drives anymore. Optical Media • Optical disks are very much like hard disks • Hard disks store information using magnetic material • Bits are stored by changing the magnetic properties of the magnetic material • Bits are read by picking up the tiny magnetic field with a read head • Optical disks store information as pits in a physical medium • A laser is used to determine if a pit is present or not. DVD – Digital Versatile Disk • DVDs hold approx 7 times the information that CDs do in the same amount of storage space • DVDs come in 3 types • Single Sided/Single Layer (4.7 GB) • Single Sided/Double Layer (8.5 GB) • Double Sided/Double Layer (17 GB) • DVD uses a laser with a shorter wavelength so the pits are smaller • More pits can be stored on a DVD • Narrower track Pen Drive A pen drive being inserted into a USB port.