TRAINERS TRAINING ON COMPUTER MAINTENANCE AND TROUBLE SHOOTING

TRAINERS TRAINING ON COMPUTER MAINTENANCE AND TROUBLE SHOOTING

Seminar Workshop Objectives:
Acquire better understanding on the different types of Operating System for the proper diagnosis and repair of computer problems. Enhance skill in installing different types of Application Software and in configuring different peripherals. Develop expertise in network and trouble shooting.

Computer Hardware and Peripherals

Motherboards Motherboards (also called mainboards) are actually a carryover from architecture used for years in mainframe computers. Various circuit cards performing various functions all plug into many similar sockets on a common circuit board. Each circuit card performs a unique function in the computer and gets its power from the socket.

MSI 694D Pro AR Dual Flip Chip Socket 370 motherboard
The Abit KT-7A supports Advanced Micro Devices (AMD) processors and has the KT-133A chipset. The card slots on the Abit KT-7A, from bottom to top in the image below, shows that ISA has one slot, PCI has six slots and AGP has one slot. A special fan cools the chipset. MSI 694D Pro AR Dual Flip Chip Socket 370 motherboard

Abit KT-7A AMD Processor Motherboard
A partial view of the TechRam S3ProM motherboard shows slots: From bottom to top, ISA has one slot, PCI has two slots, audio modem riser (AMR) has one slot, and AGP has one slot. Abit KT-7A AMD Processor Motherboard

Data Bus Width Modern Pentium class motherboards have a data bus with 64 bits. That is the width of the data highway that goes in and out of the processor. The Pentium processors, however, do use 32-bit registers to handle 32-bit instructions. Bus speeds and widths have increased due to faster processors and the needs of multimedia applications.

Typical bus names and widths are:
Industry Standard Architecture (ISA) - 8 or 16 bits Extended Industry Standard Architecture (EISA) - 8 or16 bits Microchannel Architecture (MCA) - 16 or 32 bits VESA Local Bus (VLB) - 32 bits Peripheral Component Interconnect (PCI) - 32 or 64 bits Accelerated Graphics Port (AGP ) - 32 bits

Microprocessors A microprocessor -- also known as a CPU or central processing unit -- is a complete computation engine that is fabricated on a single chip. The first microprocessor was the Intel 4004, introduced in The 4004 was not very powerful -- all it could do was add and subtract, and it could only do that 4 bits at a time. But it was amazing that everything was on one chip. Prior to the 4004, engineers built computers either from collections of chips or from discrete components (transistors wired one at a time). The 4004 powered one of the first portable electronic calculators.

Microprocessor Progression: Intel
Name Date Transistors Microns Clock speed Data width MIPS 8080 1974 6,000 6 2 MHz 8 bits 0.64 8088 1979 29,000 3 5 MHz 16 bits 8-bit bus 0.33 80286 1982 134,000 1.5 6 MHz 16 bits 1 80386 1985 275,000 16 MHz 32 bits 5 80486 1989 1,200,000 25 MHz 20 Pentium 1993 3,100,000 0.8 60 MHz 32 bits 64-bit bus 100 Pentium II 1997 7,500,000 0.35 233 MHz ~300 Pentium III 1999 9,500,000 0.25 450 MHz ~510 Pentium 4 2000 42,000,000 0.18 1.5 GHz ~1,700

Information about this table:
The date is the year that the processor was first introduced. Many processors are re-introduced at higher clock speeds for many years after the original release date. Transistors is the number of transistors on the chip. You can see that the number of transistors on a single chip has risen steadily over the years. Microns is the width, in microns, of the smallest wire on the chip. For comparison, a human hair is 100 microns thick. As the feature size on the chip goes down, the number of transistors rises. Clock speed is the maximum rate that the chip can be clocked at. Clock speed will make more sense in the next section.

Information about this table:
Data Width is the width of the ALU. An 8-bit ALU can add/subtract/multiply/etc. two 8-bit numbers, while a 32-bit ALU can manipulate 32-bit numbers. An 8-bit ALU would have to execute four instructions to add two 32-bit numbers, while a 32-bit ALU can do it in one instruction. MIPS stands for "millions of instructions per second" and is a rough measure of the performance of a CPU.

Computer Memory memory is technically any form of electronic storage, it is used most often to identify fast, temporary forms of storage. If your computer's CPU had to constantly access the hard drive to retrieve every piece of data it needs, it would operate very slowly. When the information is kept in memory, the CPU can access it much more quickly. Most forms of memory are intended to store data temporarily. A Sony Flash Memory Stick

Types of Electronic Memory
RAM ROM Cache Dynamic RAM Static RAM Flash memory Memory Sticks Virtual memory Video memory BIOS RAM memory modules From the top: SIMM, DIMM and SODIMM

Memory Basics The CPU accesses memory according to a distinct hierarchy. Whether it comes from permanent storage (the hard drive) or input (the keyboard), most data goes in random access memory (RAM) first. The CPU then stores pieces of data it will need to access, often in a cache, and maintains certain special instructions in the register.

ROM Read-only memory (ROM), also known as firmware, is an integrated circuit programmed with specific data when it is manufactured. ROM chips are used not only in computers, but in most other electronic items as well.

ROM Types ROM PROM EPROM EEPROM Flash memory

ROM Similar to RAM, ROM chips contain a grid of columns and rows. But where the columns and rows intersect, ROM chips are fundamentally different from RAM chips. While RAM uses transistors to turn on or off access to a capacitor at each intersection, ROM uses a diode to connect the lines if the value is 1. If the value is 0, then the lines are not connected at all.

PROM Creating ROM chips totally from scratch is time-consuming and very expensive in small quantities. For this reason, mainly, developers created a type of ROM known as programmable read-only memory (PROM). Blank PROM chips can be bought inexpensively and coded by anyone with a special tool called a programmer.

EPROM Erasable programmable read-only memory (EPROM) addresses this issue. EPROM chips can be rewritten many times. Erasing an EPROM requires a special tool that emits a certain frequency of ultraviolet (UV) light. EPROMs are configured using an EPROM programmer that provides voltage at specified levels depending on the type of EPROM used.

EEPROMs and Flash Memory
Electrically erasable programmable read-only memory (EEPROM) Though EPROMs are a big step up from PROMs in terms of reusability, they still require dedicated equipment and a labor-intensive process to remove and reinstall them each time a change is necessary. Also, changes cannot be made incrementally to an EPROM; the whole chip must be erased. Flash memory, a type of EEPROM that uses in-circuit wiring to erase by applying an electrical field to the entire chip or to predetermined sections of the chip called blocks. Flash memory works much faster than traditional EEPROMs because it writes data in chunks, usually 512 bytes in size, instead of 1 byte at a time.

RAM Random access memory (RAM) is the best known form of computer memory. RAM is considered "random access" because you can access any memory cell directly if you know the row and column that intersect at that cell. The opposite of RAM is serial access memory (SAM). SAM stores data as a series of memory cells that can only be accessed sequentially (like a cassette tape).

Common RAM Types SRAM Static random access memory uses multiple transistors, typically four to six, for each memory cell but doesn't have a capacitor in each cell. It is used primarily for cache. DRAM Dynamic random access memory has memory cells with a paired transistor and capacitor requiring constant refreshing. FPMDRAM Fast page mode dynamic random access memory was the original form of DRAM. It waits through the entire process of locating a bit of data by column and row and then reading the bit before it starts on the next bit. Maximum transfer rate to L2 cache is approximately 176 MBps.

EDODRAM Extended data-out dynamic random access memory does not wait for all of the processing of the first bit before continuing to the next one. As soon as the address of the first bit is located, EDO DRAM begins looking for the next bit. It is about five percent faster than FPM. Maximum transfer rate to L2 cache is approximately 264 MBps. SDRAM Synchronous dynamic random access memory takes advantage of the burst mode concept to greatly improve performance. The idea is that most of the time the data needed by the CPU will be in sequence. SDRAM is about five percent faster than EDO RAM and is the most common form in desktops today. Maximum transfer rate to L2 cache is approximately 528 MBps.

DDRSDRAM Double data rate synchronous dynamic RAM is just like SDRAM except that is has higher bandwidth, meaning greater speed. Maximum transfer rate to L2 cache is approximately 1,064 MBps (for DDR SDRAM 133 MHZ). RDRAM Rambus dynamic random access memory is a radical departure from the previous DRAM architecture. Designed by Rambus, RDRAM uses a Rambus in-line memory module (RIMM), which is similar in size and pin configuration to a standard DIMM. What makes RDRAM so different is its use of a special high-speed data bus called the Rambus channel. RDRAM memory chips work in parallel to achieve a data rate of 800 MHz, or 1,600 MBps.

Credit Card Memory Credit card memory is a proprietary self-contained DRAM memory module that plugs into a special slot for use in notebook computers. PCMCIA Memory Card Another self-contained DRAM module for notebooks, cards of this type are not proprietary and should work with any notebook computer whose system bus matches the memory card's configuration.

CMOSRAM CMOS RAM is a term for the small amount of memory used by your computer and some other devices to remember things like hard disk settings. This memory uses a small battery to provide it with the power it needs to maintain the memory contents. VRAM VideoRAM, also known as multiport dynamic random access memory (MPDRAM), is a type of RAM used specifically for video adapters or 3-D accelerators. The "multiport" part comes from the fact that VRAM normally has two independent access ports instead of one, allowing the CPU and graphics processor to access the RAM simultaneously. VRAM is located on the graphics card and comes in a variety of formats, many of which are proprietary. The amount of VRAM is a determining factor in the resolution and color depth of the display.

IDE Controllers Integrated Drive Electronics (IDE) interface. Essentially, an IDE interface is a standard way for a storage device to connect to a computer. IDE is actually not the true technical name for the interface standard. The original name, AT Attachment (ATA), signified that the interface was initially developed for the IBM AT computer. A close-up of the primary and secondary IDE interfaces on a motherboard

Cable Key IDE devices use a ribbon cable to connect to each other. Ribbon cables have all of the wires laid flat next to each other instead of bunched or wrapped together in a bundle. IDE ribbon cables have either 40 or 80 wires. There is a connector at each end of the cable and another one about two-thirds of the distance from the motherboard connector.

USB Ports Just about any computer that you buy today comes with one or more Universal Serial Bus connectors on the back. These USB connectors let you attach everything from mice to printers to your computer quickly and easily. The operating system supports USB as well, so the installation of the device drivers is quick and easy, too.

Sample List of USB Devices
Printers Scanners Mice Joysticks Digital cameras Webcams Modems Speakers Telephones Network connections The rectangular socket is a typical USB socket on the back of a PC

The USB standard uses "A" and "B" connectors to avoid confusion:
"A" connectors head "upstream" toward the computer. "B" connectors head "downstream" and connect to individual devices.

Serial Ports Considered to be one of the most basic external connections to a computer, the serial port has been an integral part of most computers. Serial ports provide a standard connector and protocol to let you attach devices, such as modems, to your computer.

The Serial Connection

9-pin connector: 1. Carrier Detect - Determines if the modem is connected to a working phone line. 2. Receive Data - Computer receives information sent from the modem. 3. Transmit Data - Computer sends information to the modem. 4. Data Terminal Ready - Computer tells the modem that it is ready to talk. 5. Signal Ground - Pin is grounded. 6. Data Set Ready - Modem tells the computer that it is ready to talk. 7. Request To Send - Computer asks the modem if it can send information. 8. Clear To Send - Modem tells the computer that it can send information. 9. Ring Indicator - Once a call has been placed, computer acknowledges signal (sent from modem) that a ring is detected.

25-pin connector: 1. Not Used
2. Transmit Data - Computer sends information to the modem. 3. Receive Data - Computer receives information sent from the modem. 4. Request To Send - Computer asks the modem if it can send information. 5. Clear To Send - Modem tells the computer that it can send information. 6. Data Set Ready - Modem tells the computer that it is ready to talk. 7. Signal Ground - Pin is grounded.

25-pin connector: 8. Received Line Signal Detector - Determines if the modem is connected to a working phone line. 9. Not Used: Transmit Current Loop Return (+) 10. Not Used 11. Not Used: Transmit Current Loop Data (-) 12. Not Used 13. Not Used 14. Not Used 15. Not Used 16. Not Used 17. Not Used 18. Not Used: Receive Current Loop Data (+)

25-pin connector: 19. Not Used
20. Data Terminal Ready - Computer tells the modem that it is ready to talk. 21. Not Used 22. Ring Indicator - Once a call has been placed, computer acknowledges signal (sent from modem) that a ring is detected. 23. Not Used 24. Not Used 25. Not Used: Receive Current Loop Return (-) A dual serial port card

A typical parallel port on the back of your computer
Parallel Ports Parallel ports were originally developed by IBM as a way to connect a printer to your PC. When IBM was in the process of designing the PC, the company wanted the computer to work with printers offered by Centronics, a top printer manufacturer at the time. A typical parallel port on the back of your computer

Parallel ports can be used to connect a host of popular computer peripherals:
Printers Scanners CD burners External hard drives Iomega Zip removable drives Network adapters

SCSI devices usually connect to a controller card like this one
Most home and small-office PCs use an IDE hard drive and have a PCI bus for adding components to the computer. But a lot of computers, particularly high-end workstations and older Apple Macintoshes, use the Small Computer System Interface (SCSI) bus to connect components, which may include: Hard drives Scanners CD-ROM/RW drives Printers SCSI devices usually connect to a controller card like this one

Kinds of SCSI Connectors
Internal SCSI devices connect to a 50-pin ribbon cable DB-25 SCSI connector

68-pin Alternative 3 SCSI connector 50-pin Centronics SCSI connector

External SCSI devices connect using thick, round cables Internal SCSI devices connect to a ribbon cable

Peripheral Component Interconnect (PCI)
PCI cards use 47 pins A typical PCI card

Hard Disks Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes. They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product).

Capacity and Performance
There are two ways to measure the performance of a hard disk: Data rate - The data rate is the number of bytes per second that the drive can deliver to the CPU. Rates between 5 and 40 megabytes per second are common. Seek time - The seek time is the amount of time between when the CPU requests a file and when the first byte of the file is sent to the CPU. Times between 10 and 20 milliseconds are common. The other important parameter is the capacity of the drive, which is the number of bytes it can hold.

Inside: Electronics Board
It is a sealed aluminum box with controller electronics attached to one side. The electronics control the read/write mechanism and the motor that spins the platters.

Inside: Beneath the Board
Underneath the board are the connections for the motor that spins the platters, as well as a highly-filtered vent hole that lets internal and external air pressures equalize:

Inside: Platters and Heads
In order to increase the amount of information the drive can store, most hard disks have multiple platters. This drive has three platters and six read/write heads:

Storing the Data Data is stored on the surface of a platter in sectors and tracks. Tracks are concentric circles, and sectors are pie-shaped wedges on a track A typical track is shown in yellow; a typical sector is shown in blue. A sector contains a fixed number of bytes -- for example, 256 or 512. Either at the drive or the operating system level, sectors are often grouped together into clusters.

Floppy Disk Drives The floppy disk drive (FDD) was the primary means of adding data to a computer until the CD-ROM drive became popular. Basically, a floppy disk drive reads and writes data to a small, circular piece of metal-coated plastic similar to audio cassette tape.

The major parts of a FDD include:
Read/Write Heads Drive Motor Stepper Motor Mechanical Frame Circuit Board

PC Power Supplies In a personal computer (PC), the power supply is the metal box usually found in a corner of the case. The power supply is visible from the back of many systems because it contains the power-cord receptacle and the cooling fan.

Power Supply Wattage PC Item Watts
Accelerated Graphics Port (AGP) card 20 to 30W Peripheral Component Interconnect (PCI) card 5W small computer system interface (SCSI) PCI card 20 to 25W floppy disk drive network interface card 4W 50X CD-ROM drive 10 to 25W RAM 10W per 128M 5200 RPM Integrated Drive Electronics (IDE) hard disk drive 5 to 11W 7200 RPM IDE hard disk drive 5 to 15W Motherboard (without CPU or RAM) 550 MHz Pentium III 30W 733 MHz Pentium III 23.5W 300 MHz Celeron 18W 600 MHz Athlon 45W

This Microsoft Intellimouse uses optical technology
Computer Mice A pointing device used to select various options. This Microsoft Intellimouse uses optical technology

Inside a Mouse A ball inside the mouse touches the desktop and rolls when the mouse moves. Two rollers inside the mouse touch the ball. One of the rollers is oriented so that it detects motion in the X direction, and the other is oriented 90 degrees to the first roller so it detects motion in the Y direction. When the ball rotates, one or both of these rollers rotate as well.

Inside a Mouse The rollers each connect to a shaft, and the shaft spins a disk with holes in it. When a roller rolls, its shaft and disk spin. An on-board processor chip reads the pulses from the infrared sensors and turns them into binary data that the computer can understand.

Inside a Mouse On either side of the disk there is an infrared LED and an infrared sensor. The holes in the disk break the beam of light coming from the LED so that the infrared sensor sees pulses of light. The rate of the pulsing is directly related to the speed of the mouse and the distance it travels.

Data Interface Most mice in use today use the standard PS/2 type connector. These pins have the following functions 1. Unused 2. +5 volts (to power the chip and LEDs) 3. Unused 4. Clock 5. Ground 6. Data A typical PS/2 connector: Assume that pin 1 is located just to the left of the black alignment pin, and the others are numbered clockwise from there.

Computer Keyboards The part of the computer that we come into most contact with is probably the piece that we think about the least. But the keyboard is an amazing piece of technology. An Apple Extended keyboard

Types of Keyboards 101-key Enhanced keyboard 104-key Windows keyboard
82-key Apple standard keyboard 108-key Apple Extended keyboard

microprocessor and controller circuitry of a keyboard
Inside the Keyboard rubber dome switches microprocessor and controller circuitry of a keyboard key matrix rubber dome

BIOS One of the most common uses of Flash memory is for the basic input/output system of your computer, commonly known as the BIOS (pronounced "bye-ose"). On virtually every computer available, the BIOS makes sure all the other chips, hard drives, ports and CPU function together. The BIOS is special software that interfaces the major hardware components of your computer with the operating system. It is usually stored on a Flash memory chip on the motherboard, but sometimes the chip is another type of ROM.

What BIOS Does When you turn on your computer, the BIOS does several things. This is its usual sequence: 1. Check the CMOS Setup for custom settings 2. Load the interrupt handlers and device drivers 3. Initialize registers and power management 4. Perform the power-on self-test (POST) 5. Display system settings 6. Determine which devices are bootable 7. Initiate the bootstrap sequence

Configuring BIOS To enter the CMOS Setup, you must press a certain key or combination of keys during the initial startup sequence. Most systems use "Esc," "Del," "F1," "F2," "Ctrl-Esc" or "Ctrl-Alt-Esc" to enter setup. Once you have entered setup, you will see a set of text screens with a number of options.

Common options include:
System Time/Date - Set the system time and date Boot Sequence - The order that BIOS will try to load the operating system Plug and Play - A standard for auto-detecting connected devices; should be set to "Yes" if your computer and operating system both support it CMOS Setup

Common options include:
Mouse/Keyboard - "Enable Num Lock," "Enable the Keyboard," "Auto-Detect Mouse"... Drive Configuration - Configure hard drives, CD-ROM and floppy drives Memory - Direct the BIOS to shadow to a specific memory address Security - Set a password for accessing the computer Power Management - Select whether to use power management, as well as set the amount of time for standby and suspend Exit - Save your changes, discard your changes or restore default settings

Preventive Maintenance

Preventive Maintenance
Cleaning of Computer, Keyboard and Printer Cleaning of Pointing Device Taking care of Computer To take care of your CD’s

Cleaning of Computer, Keyboard and Printer
Turn off the computer and unplug the power cord Use soft cloth moistened with water an gently wipe the exterior of the computer, keyboard and printer.

Cleaning of Pointing Device
Open the circular cover underneath the mouse Take out the rubber ball and wipe it with a soft, damp cloth Put the ball and close the cover

Taking care of Computer
Do not expose the computer to direct sunlight Do not subject the computer to magnetic fields Do not expose the computer to dust and dirt Never place the system on uneven surfaces

To take care of your CD’s
Keep your disc in its case when not in use to avoid scratches or other damage. When cleaning disc, use a clean, dust free cloth and wipe in a straight line from the center to the edge. Clean your CD drive periodically.

Troubleshooting

Troubleshooting No Display No Power Boot-up Problem Keyboard Problem
Mouse Problem Floppy Disk Drive Problem Printing Problem

No Display Check cable connections Try restarting the computer
Test the computer with other monitor

No Power Check AC output voltage Check power cable connections
Check the computer power supply

Boot-up Problem Check CMOS configuration
Remove any disk inserted in the floppy drive

Keyboard Problem Reseat connections Replace with other keyboard
Try re-starting

Mouse Problem Reseat connection Replace with other mouse
Try restarting

Floppy Disk Drive Problem
Check CMOS configuration Try using another set of diskette Clean drive with Disk Cleaner

Printing Problems Check printer power Check cable connections
Check ink cartridge Replace printer cable

For Technical Assistance
You may contact, Mr. Pete D. Rabago Ayala Foundation, Inc. 10/F BPI Main Bldg Ayala Avenue cor Paseo de Roxas, Makati City Or call (632)

Operating System

Operating Systems The operating system defines our computing experience. It's the first software we see when we turn on the computer, and the last software we see when the computer is turned off. It's the software that enables all the programs we use.

At the simplest level, an operating system does two things:
It manages the hardware and software resources of the computer system. These resources include such things as the processor, memory, disk space, etc. It provides a stable, consistent way for applications to deal with the hardware without having to know all the details of the hardware.

The operating system's tasks, in the most general sense, fall into six categories:
Processor management Memory management Device management Storage management Application interface User interface

Hardware Configuration

AGP Accelerated Graphics Port AGP and AGP graphics cards are now the standard for processing graphics on computers. Like all hardware, the technology and specifications are constantly improving.

Computer Monitors An output device that displays information.
Often referred to as a monitor when packaged in a separate case, the display is the most-used output device on a computer. The display provides instant feedback by showing you text and graphic images as you work or play.

number of colors different bit depths
1 2 (monochrome) 2 4 (CGA) 4 16 (EGA) 8 256 (VGA) 16 65,536 (High Color, XGA) 24 16,777,216 (True Color, SVGA) 32 16,777,216 (True Color + Alpha Channel) Sony flat-panel display

Industry Standard Architecture 16-bit sound card
Sound Cards The voice in your computer that lets you know when you've received a new is made possible by the sound card. Before the arrival of sound cards, personal computers (PCs) were limited to beeps from a tiny speaker on the motherboard. In 1989, Creative Labs introduced the Creative Labs SoundBlaster® card. Industry Standard Architecture 16-bit sound card

Anatomy of a Sound Card A typical sound card has:
a digital signal processor (DSP) that handles most computations a digital to analog converter (DAC) for audio leaving the computer an analog-to-digital converter (ADC) for audio coming into the computer

Anatomy of a Sound Card read-only memory (ROM) or Flash memory for storing data musical instrument digital interface (MIDI) for connecting to external music equipment (for many cards, the game port is also used to connect an external MIDI adapter) jacks for connecting speakers and microphones, as well as line in and line out a game port for connecting a joystick or gamepad

Sound cards may be connected to:
headphones amplified speakers an analog input source microphone radio tape deck CD player a digital input source digital audiotape (DAT) CD-ROM drive an analog output device - tape deck a digital output device DAT CD recordable (CD-R)

Modems The word "modem" is a contraction of the words modulator-demodulator. A modem is typically used to send digital data over a phone line.

Modem Speeds 300 bps - 1960s through 1983 or so
1200 bps - Gained popularity in 1984 and 1985 2400 bps 9600 bps - First appeared in late 1990 and early 1991 19.2 kilobits per second (Kbps) 28.8 Kbps 33.6 Kbps 56 Kbps - Became the standard in 1998 ADSL, with theoretical maximum of up to 8 megabits per second (Mbps) - Gained popularity in 1999

CD Burners An external writable CD drive, also called a CD burner: With this type of drive, you can take music or data files from your computer and make your own CDs. Today, writable CD drives (CD burners) are standard equipment in new PCs, and more and more audio enthusiasts are adding separate CD burners to their stereo systems.

Laser Assembly The CD burner has a moving laser assembly, just like an ordinary CD player. But in addition to the standard "read laser," it has a "write laser." The write laser is more powerful than the read laser, so it interacts with the disc differently. The laser assembly inside a CD burner

Scanners Scanners have become an important part of the home office over the last few years. Scanner technology is everywhere and used in many ways: Flatbed scanners Sheet-fed scanners Handheld scanners Drum scanners

Parts of a typical flatbed scanner include:
Charge-coupled device (CCD) array Mirrors Scan head Glass plate Lamp Lens Cover Filters Stepper motor Stabilizer bar Belt Power supply Interface port(s) Control circuitry

There are three common connections used by scanners:
Parallel Small Computer System Interface (SCSI) Universal Serial Bus (USB)

Digital Cameras The digital camera is one of the most remarkable instances of this shift because it is so truly different from its predecessor. All digital cameras have a built-in computer, and all of them record images in an entirely electronic form.

Some typical resolutions that you find in digital cameras
256x256 pixels 640x480 pixels 1216x912 pixels 1600x1200 pixels Image Capacity Image Size TIFF (uncompressed) JPEG (high quality) JPEG (medium quality) 640x480 1.0 MB 300 KB 90 KB 800x600 1.5 MB 500 KB 130 KB 1024x768 2.5 MB 800 KB 200 KB 1600x1200 6.0 MB 1.7 MB 420 KB

number of storage systems currently used in digital cameras
Built-in memory - Some extremely inexpensive cameras have built-in Flash memory. SmartMedia cards - SmartMedia cards are small Flash memory modules. CompactFlash - CompactFlash cards are another form of Flash memory, similar to but slightly larger than SmartMedia cards. Memory Stick - Memory Stick is a proprietary form of Flash memory used by Sony. Floppy disk - Some cameras store images directly onto floppy disks. Hard disk - Some higher-end cameras use small built-in hard disks, or PCMCIA hard-disk cards, for image storage. Writeable CD and DVD - Some of the newest cameras are using writeable CD and DVD drives to store images.

Inkjet Printers An inkjet printer is any printer that places extremely small droplets of ink onto paper to create an image.

Impact vs. Non-impact There are several major printer technologies available. These technologies can be broken down into two main categories with several types in each: Impact - These printers have a mechanism that touches the paper in order to create an image. Non-impact - These printers do not touch the paper when creating an image.

There are two main impact technologies:
Dot matrix printers use a series of small pins to strike a ribbon coated with ink, causing the ink to transfer to the paper at the point of impact. Character printers are basically computerized typewriters. They have a ball or series of bars with actual characters (letters and numbers) embossed on the surface.

Non-impact technologies:
Laser printers, covered in-depth in use dry ink (toner), static electricity, and heat to place and bond the ink onto the paper. Inkjet printers, which are described in this article, use a series of nozzles to spray drops of ink directly on the paper. Solid ink printers contain sticks of wax-like ink that are melted and applied to the paper. Dye-sublimation printers have a long roll of transparent film that resembles sheets of red-, blue-, yellow- and gray-colored cellophane stuck together end to end.

Non-impact technologies:
Thermal wax printers are something of a hybrid of dye-sublimation and solid ink technologies. They use a ribbon with alternating CMYK color bands. Thermal autochrome printers have the color in the paper instead of in the printer. There are three layers (cyan, magenta and yellow) in the paper, and each layer is activated by the application of a specific amount of heat.

Inside an Inkjet Printer
1. Print head assembly Print head Ink cartridges Print head stepper motor Belt Stabilizer bar

2. Paper feed assembly Paper tray/feeder Rollers Paper feed stepper motor

3. Power supply 4. Control circuitry 5. Interface port(s)

Application Software Installation

Application Software Installation
MS – Office 97 MS – Office 2000 MS – Office XP

MS - DOS Basics Format Command Directory Command DIR Command
EDIT Command COPY Command PATH Command REN Command ATTRIB Command DEL Command CHKDSK Command

MS - DOS Basics a. C:> FORMAT A: b. C:> FORMAT A:/S
Format Command Prepares a diskette for use or wipes out all data from the disk. a. C:> FORMAT A: b. C:> FORMAT A:/S c. C:> FORMAT A:/V d. C:> FORMAT A:/S/V/Q

MS - DOS Basics C:> DIR C:> DIR / P C:> DIR / W
Displays the contents of a disk or a directory. DIR Command C:> DIR C:> DIR / P C:> DIR / W C:> DIR / P / W C:> DIR / B C:> DIR / L

MS - DOS Basics Syntax: C:> COPY <source> <destination>
COPY Command Copies a file or a group of files from one disk to another or from one directory to another. Syntax: C:> COPY <source> <destination>

Syntax: C:> REN <old filename> <new filename>
MS - DOS Basics REN Command Renames file or a group of files. Syntax: C:> REN <old filename> <new filename>

C:> DEL <filename>
MS - DOS Basics DEL Command Deletes or erases a file or a group of files from disk or a directory. C:> DEL <filename>

MS - DOS Basics Directory Command MD –creates a directory
CD –changes current / working directory RD –removes a directory CD\ - makes root directory as the current directory CD. –change to current directory CD.. –change to parent directory

MS - DOS Basics EDIT Command Ctrl Home End Ctrl

MS - DOS Basics To display the current path C:>\ PATH
PATH Command Sets the path for the command and files. To display the current path C:>\ PATH b. To set the path C:>\ PATH =C:>\<dirname1>; C:\<dirname2>

MS - DOS Basics ATTRIB Command To display the attributes of a file
Display or changes the attributes of a file or group of files. To display the attributes of a file C:>\attrib <filename> b. To unprotect a file in DOS C:>\attrib –r a:<filename> c. To make a file hidden C:>\attrib +h a:<filename> d. To remove the hidden attribute of a file C:>\attrib –h a:<filename>

MS - DOS Basics To display only the status of a disk
CHKDSK Command Display the contents of a disk, including hidden files; displays also the status of a disk. To display only the status of a disk C:>\CHKDSK A:> b. To display the status and the contents of disk including the files C:>\CHKDSK A:/V

Network Concept

Local Area Network (LAN)
An Ethernet card, on the other hand, connects directly to the computer's bus. Ethernet cards come in two flavors: one that accepts 10 Mbps, and another that accepts 100 Mbps.

Why Network? Networking allows one computer to send information to and receive information from another. Certainly the Internet is the most conspicuous example of computer networking, linking millions of computers around the world, but smaller networks play a roll in information access on a daily basis.

Local Area vs. Wide Area Local area network (LAN) technologies connect many devices that are relatively close to each other, usually in the same building. The library terminals that display book information would connect over a local area network. Wide area network (WAN) technologies connect a smaller number of devices that can be many kilometers apart.

The Ethernet In 1973, at Xerox Corporation’s Palo Alto Research Center (more commonly known as PARC), researcher Bob Metcalfe designed and tested the first Ethernet network. While working on a way to link Xerox’s "Alto" computer to a printer, Metcalfe developed the physical method of cabling that connected devices on the Ethernet as well as the standards that governed communication on the cable.

Ethernet Basics Ethernet is a local area technology, with networks traditionally operating within a single building, connecting devices in close proximity. Ethernet devices could have only a few hundred meters of cable between them, making it impractical to connect geographically dispersed locations. Modern advancements have increased these distances considerably, allowing Ethernet networks to span tens of kilometers.

Ethernet Terminology Medium - Ethernet devices attach to a common medium that provides a path along which the electronic signals will travel. Historically, this medium has been coaxial copper cable, but today it is more commonly a twisted pair or fiber optic cabling.

Ethernet Terminology Segment - We refer to a single shared medium as an Ethernet segment. Node - Devices that attach to that segment are stations or nodes. Frame - The nodes communicate in short messages called frames, which are variably sized chunks of information.

Ethernet Medium

Bridges To alleviate problems with segmentation, Ethernet networks implemented bridges. Bridges connect two or more network segments, increasing the network diameter as a repeater does, but bridges also help regulate traffic.

Switched Ethernet Modern Ethernet implementations often look nothing like their historical counterparts. Where long runs of coaxial cable provided attachments for multiple stations in legacy Ethernet, modern Ethernet networks use twisted pair wiring or fiber optics to connect stations in a radial pattern.

Alternative Network Technologies: Token Ring
The most common local area network alternative to Ethernet is a network technology developed by IBM, called token ring. Where Ethernet relies on the random gaps between transmissions to regulate access to the medium, token ring implements a strict, orderly access method.

Token Ring

Illustration of a Cisco Catalyst switch
LAN Switches Switches are a fundamental part of most networks. They make it possible for several users to send information over a network at the same time without slowing each other down. Illustration of a Cisco Catalyst switch

Networking Basics

Network Topologies Bus network topology

Network Topologies Ring network topology

Network Topologies Star network topology

A typical star bus network
Network Topologies A typical star bus network

Fully Switched Networks
An example of a network using a switch

Thank You…

TRAINERS TRAINING ON COMPUTER MAINTENANCE AND TROUBLE SHOOTING

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TRAINERS TRAINING ON COMPUTER MAINTENANCE AND TROUBLE SHOOTING

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