Note: This is a list of the steps you must take with each computer. Anywhere along the way, you may need to replace parts or dig deeper to find the source of problems. The extra steps you take depend on the specific problem. [This Work Plan does not apply to classes One and Two where the computers are assembled and disassembled for the purpose of learning the components.]

This is a process to get to know one computer, its particular features, and write them down. You'll be filling out a standard TecsChange In-Process form to record what you learn. If there is a problem with your computer, or something unusual about it, write that down too!

Congratulations! You are ready for your next computer!

Attachment 14– All Classes

A number system that has just two unique digits. For most purposes, we use the decimal number system, which has ten unique digits, 0 through 9. Computers use the binary number system, which only has two unique numbers, 0 and 1. We use the decimal system in everyday life because it seems more natural (we have ten fingers and ten toes). For the computer, the binary system makes sense because it's electrical: things are either "on" or "off."

Short for binary digit, the smallest unit of information on a machine. A single bit can hold only one of two values: 0 or 1. Since one bit can’t give you very much information, 8 bits in a row make a byte, which can keep track of 256 values.

A byte is equal to 8 bits. Large amounts of memory are talked about in kilobytes (1,024 bytes), megabytes (1,048,576 bytes), and gigabytes (1,073,741,824 bytes). A disk that can hold 1.44 megabytes, for example, is capable of storing approximately 1.4 million characters, or about 3,000 pages of information.

When used to described data storage, 1,048,576 (which is 2 to the 20th power) bytes (one million bytes). Megabyte is often shortened to M or MB. When used to describe data transfer rates, as in MBps (megabytes per second). To give you an idea, one megabyte is enough to save all the words from an entire Boston Sunday Globe. Gigabyte is often shortened to Gig or GB and is equal to 1,073,741,824 (which is 2 to the 30thpower) bytes (one billion bytes).

Information usually formatted in a special way. Software can be one of two kinds: data and programs. Programs are a set of instructions for reading or using data. Data can exist in many different forms—as numbers or text on pieces of paper, as bits and bytes stored in electronic memory, or even as facts stored in a person’s mind. "Data" usually means information that a computer uses, as opposed to information that people can read.

A machine that reads data from and writes data onto a disk. A disk drive is somewhat similar to a record player: it spins the disk around, and the heads are attached to an arm that moves from the edge of the disk towards the center (just like the needle on a record player). (Moving the head between the center and the edge of the disk is call “seeking” and causes most of the noise you hear from a disk drive.) It has one or more heads that read and write data.

Unlike most hard disks, floppy disks (often called “floppies” or sometimes “diskettes”) are portable, because you can remove them from a disk drive. Disk drives for floppy disks are called “floppy disk drives” (or sometimes just “floppy drives”). Floppy disks are slower to access than hard disks and have less storage capacity, but they are much less expensive. Most important, you can take them out and put them in another floppy disk drive, so you can copy files from one computer to another

A hard disk or hard drive is a magnetic disk on which you can store computer data. Hard disks hold more data and are faster than floppy disks. A hard disk, for example, can store anywhere from a few megabytes to several gigabytes, whereas most floppies have a maximum storage capacity of 1.44 megabytes.

Partition

(verb) To divide memory or mass storage into isolated sections. In DOS systems, you can partition a disk, and each partition will behave like a separate disk drive. Partitioning is particularly useful if you run more than one operating system. In addition, partitioning on DOS and Windows machines can improve disk efficiency. This is because the FAT system used by these operating systems automatically assigns cluster size based on the disk size: the larger the disk, the larger the cluster. Unfortunately, large clusters can result in a wasted disk space.

A table that the operating system uses to locate files on a disk. Because of fragmentation, usually files are saved in many small “clusters” (sections) that are scattered around the disk. The FAT keeps track of all these pieces. In DOS systems, FATs are stored in hidden files, called FAT files. (Hidden files don’t show up when you enter the DIR command or when you are using File Manager in Windows.) The FAT is usually stored at the beginning of the drive. It lists the names, types, sizes, dates of all the files and the clusters on the disk that store the data in the files.

By using DOS’s Fdisk utility program (FDISK.EXE), a physical drive can be split into one or more partitions (or volumes). DOS supports up to four partitions on a hard drive. Each partition has a drive name (a single letter, like “C:”) and has a file allocation table. When you format a hard drive, DOS divides it into sectors (each one holds 512 bytes of data). A group of sectors is a “cluster.” A cluster is the smallest amount of disk space that can be used for files.

To prepare a disk, for reading and writing. When you format a disk, the operating system erases all bookkeeping information on the disk (the names and locations of files, for example). It also tests the disk to make sure all sectors are good, marks bad sectors (ones with scratches), and creates internal address tables that it later uses to locate information. You must format a disk before you can use it.

Note that reformatting a disk does not erase the data on the disk, only the address tables. Do not panic, therefore, if you accidentally reformat a disk that has useful data. A computer specialist should be able to recover most, if not all, of the information on the disk. You can also buy programs that enable you to recover a disk yourself.

Fragmentation is when a disk has files that are split up into pieces scattered around the disk. Fragmentation occurs naturally when you use a disk frequently, creating, deleting, and modifying files. At some point, a file becomes too large for the space originally allotted for it, so the operating system splits the file into two or more chunks. This is entirely invisible to people using the computer, but it can slow down how fast the computer can read and write data to and from a disk. The more fragmented a disk is, the more the disk drive has to search through different parts of the disk to read a single file. In DOS, you can “defragment” a disk with the DEFRAG command. You can also buy software utilities, called “disk optimizers” or “defragmenters,” that defragment disks.

Basically, “memory” means the storage areas inside the computer for data. Memory usually means storage that saves data on chips. (“Storage” or “mass storage” means tapes or disks.) In addition, the term memory is usually means physical memory: the actual chips that hold data. Some computers also use virtual memory, which expands physical memory onto a hard disk. Every computer comes with a certain amount of physical memory, usually referred to as main memory or RAM.

RAM (random-access memory): This is the same as main memory. When used by itself, the term RAM refers to read and write memory—that is, you can both write data into RAM and read data from RAM. This is in contrast to ROM, which permits you only to read data. Most RAM is volatile, which means that it requires a steady flow of electricity to maintain its contents. Whenever the power is turned off, all data that’s stored in RAM disappears and is lost.

A DOS and Windows utility program that finds and corrects errors on hard disks. ScanDisk checks the disk platters for defects and looks for lost clusters. Sometimes clusters are lost when a program “freezes” or “aborts” (the program stops responding or shuts down suddenly by itself). This happens because the program is writing information to a file on the disk, but it’s interrupted, and never has a chance to “close” the file.

Attachment 3– Classes 1& 2

A computer is an apparatus built to perform routine calculations with speed, reliability, and ease. While many parts go into a computer, some parts are more fundamental to the computer’s actual operation. These parts include:

The motherboard and CPU are like the nervous system of the computer. While the CPU is like a brain, the motherboard is like the spinal cord with nerves going out to all parts of the computer. The CPU is responsible for processing all of the info passing through your computer. Its main characteristic is speed. The motherboard is the large board in your computer covered with teeny tiny wires and transistors that connect every piece of hardware to the CPU.

The BIOS is responsible for monitoring the kinds of hardware that are currently installed in your computer. It works with the CMOS Setup Program to keep track of new parts, missing parts, and broken parts.

The “bus” is a common pathway across which data can travel within a computer. This pathway is used for communication and can be established between two or more computer elements. The term bus slots refer to the long, thin slots on the motherboard where various cards are plugged in. There are 2 types of bus slots: full slots and half slots. The full slots (ISA – Industry Standard Architecture) are longer. The half slots (PCI – Peripheral Component Interconnect) are shorter. All slots of a particular length are wired identically, so a card can go into any of the slots.

RAM is a type of memory that allows you to run several different programs at once. For instance, if you wanted to run a word-processing program and play a game at the same time, it is your RAM that provides the space to do this. RAM operates by providing temporary space onto which your computer can store stuff that it’s currently working on but not necessarily saving. RAM is sort of like scrap paper. It gets filled up with stuff you’re currently working on, but NOT stuff you’re going to save. So, RAM gives you space to scribble lots of things at the same time. And just like scrap paper gets thrown away, RAM gets erased whenever you turn off your computer or close your programs.

Using a magnet to transfer data bits, the hard disk drive can provide long-term storage of information you want to save. That way, whenever you need a copy of it, you can simply access it on the hard disk drive. Hard disk drives are not portable, in the sense that if you want to save something to use later on a different computer, you should not save it on your hard disk drive. Rather, you should consider your floppy disk drive.

The floppy disk drive works exactly like a hard disk drive, except it saves information onto small, portable disks. Unlike a hard disk drive, however, a floppy disk drive saves information onto a portable disk, so you can access the information from ANY computer that will read your disk.

CD ROM Drives use laser to transfer data to and from the CD. Most are CD Rom and can only be read. There are special drives which can also write to a special CD for recording. Most software is installed from a CD Rom Drive today.

Your monitor and video card provide one of the more obvious forms of input and output. The video card accepts input information from the motherboard and transmits this data into a picture on your monitor screen. The picture is a type of output

Each device provides one of the most direct ways for you to give commands and information to the computer. By typing or clicking, you give instructions (or input) to the computer that will respond to your instructions and create a result (output).

These ports provide places to plug a variety of input and output devices into your computer. This isn’t necessarily true. The older Serial ports are the same size as Parallel. New Serial Ports (Universial Serial Bus - USB) are smaller and faster than Parallel. Serial ports are physically smaller than parallel ports. Serial ports, therefore, tend to move information more slowly than do parallel ports. However, both are convenient and useful. Some examples of hardware that uses these ports include your mouse (serial port), printers (parallel ports), and gaming accessories like joysticks (serial ports).

· POWER SUPPLY:The basic function of the power supply is to convert the type of electrical power available at the wall socket to the type the computer circuitry can use. The power supply in a conventional desktop system is designed to convert American 120-volt, 60Hz, AC (alternating current) power into +3.3v, +5v, and +12v DC (direct current) power.

Attachment One– Classes 1 & 2

Attachment Two– Classes 1 & 2

The flat cable with 34 wires that plugs into the motherboard goes to the floppy drive. There is a twist in the cable toward the end. A drive that plugs in after the twist becomes an A: drive. If a drive is connected before the twist, it will function as a B: drive. Some cables have two different types of connectors -- just use the type that matches the drive that you are trying to connect.

The wider flat cable with 40 wires and no twist goes to the hard drive and the CD-ROM. This is the IDE (also called E-IDE or ATA) cable. Usually, two of this kind of cable can plug into the motherboard, called Primary Channel and Secondary Channel. Usually the main hard drive is set up on the Primary channel as the first device, called Master. A CD-ROM can be on the same cable as a second device, called Slave, or on a separate Secondary cable, either as Master or Slave. All IDE devices have three jumper settings, next to the cable connection, labeled Master, Slave, and Cable Select. If there is only one device on an IDE channel, sometimes it is called Single instead of Master, and sometimes there is a separate jumper setting for this situation. Hard drives should never be set to Slave without a Master device present on the same channel, but it is sometimes OK to set up CD-ROM drives that way.

All drives also have a four-pin power connection. Sometimes the connections have to be wiggled gently but firmly to seat them properly, or unplug them. Most connections use some special shape or trick to keep you from plugging them in backwards -- examine each one carefully to understand how they work. Never change any computer connections with the power on! If you are nervous, make sure the power is unplugged before you work inside the computer. It is also best to settle yourself down and then touch the metal computer case before touching the electronics inside, to avoid damage from static electricity. This is a special concern in the winter, when the air is dry.

Flat cables have a stripe on one edge, marking the pin-one edge of the double-row header connector.

CD-ROM drives have a place to connect a special audio cable, which goes to the sound card. This is a nice extra feature, but not necessary for most uses.

If there is a wider 50-wire cable, that is for a special kind of drive called SCSI.

There are power wires from the power supply to the motherboard, usually two connectors - put the black wires together when you plug them in. There is also often a power wire from the power supply to the ON/OFF switch on the front panel. The connections to this switch may expose 120 volts of line current - this is the most dangerous place to touch in the computer - you could get a bad shock! Stay away from touching behind the power switch unless you are sure the power is unplugged.

There are usually many other little wires, that go to the fans, speakers, and lights and switches on the front panel. Every computer is different, and the best way to know how to connect them is to look at another of the same kind. Also, there is usually tiny lettering on the motherboard to let you know what should be plugged in there. Whenever you turn on a computer with the cover off, check to make sure that all fans are turning. If they aren't, find out why --or something may overheat and burn up.

Modern computer memory comes on plug-in flat sticks of various kinds. Only use the kind of memory that the computer has proper slots for. Each kind takes some experience to feel comfortable with, and some practice to get the feel of putting it in and taking it out. It is important to arrange a good workspace with good access to the memory slots in the computer, and good lighting, so you can see and understand what you are doing, especially for your first experiences. Some kinds of memory in certain computers can be a real bear to get in properly!

Older 286, 386, and 486 computers used 30-pin SIMMs (Single Inline Memory Modules). The fastest versions were 70 and 60 nS (nano-seconds, billionths of a second). The biggest sizes in ordinary use were 1M (megabyte) and 4M per stick, and were usually used in sets of four. Most computers had eight slots.

486 and Pentium computers used 72-pin SIMMs. Again, the fastest ordinary speeds were 70 and 60 nS. The most common sizes are 4M and 16M sticks. 8M sticks are also frequent, but can be harder to use in older computers. Many computers require matched pairs. Four slots are most common. Many computers also have some memory built in to the motherboard, usually 4M or 8M.

Often, if the computer has no memory installed, or there is a problem with the memory, the computer will make a special pattern of beeps when it is turned on.

Pentium and later computers use 168-pin 3.3V DIMMs. There are usually just a few slots, and single sticks can be used by themselves. Common sizes are 16M, 64M, and 128M. This is the best kind of memory today, very cheap. Some older computers won't be able to use properly sticks that have too much memory on them.

Attachment 7– Class Four

CHECKIT

The CheckIt Program is a diagnostic program: just like a doctor will diagnose your state of health, CheckIt will diagnose your computer’s health. CheckIt tests all of the hardware in a computer and tells you if the hardware is working properly. This program also gives you information about the hardware. CheckIt was written in 1989 (it’s very old by computer standards), so some of the information it provides is not useful these days. But, generally, CheckIt is helpful for figuring out what parts of your computer are working and which parts need repair or changing.

CheckIt is a menu-driven program. In other words, you use the menus at the top of the screen to choose which tests to run or what information you want to see, and you use the menu to exit the program, as well.

Together with your tutor and classmates, you will now explore CheckIt.

Here is a list of the menus and what each menu includes:

· SYSINFO: (for System Information) Use this menu to get information about what kinds of hardware are in the computer. This information is referred to as the computer’s configuration. This menu also allows you to see what information about the hardware is contained in the CMOS. (See CMOS page for more information) Because of the age of the program, it will not be able to submit accurate information about the new computers.

· BENCHMARKS: This menu has tests that measure how fast your computer runs. However, this test is pretty old and, therefore, not very useful.

· TOOLS: DO NOT GO THERE! Tests on this menu are from the old days, and can permanently damage the hard disk drive!! These tests can also mess up the computer's memory!

· SETUP: The options in this menu affect how CheckIt, itself, looks and tell CheckIt where to store reports from its tests.

· EXIT: This ends CheckIt and takes you back to the DOS prompt.

· TESTS: This menu contains all of the tests that we will be using. Due to age of the CheckIt program, not all of the tests are useful on the newer computers. For example, we do not use the following tests: Memory and Hard Disk. Most of these tests are pretty slow, so get ready to be VERY patient! :

· Hard Disk: We do not use this test to check the hard drives in the computers that we have. If we did the process would be as follows. pick “Drive 0” for the C: drive. There are four parts to this test:

1. Controller Diagnostics: Tests to see if the computer’s controller card for the disk drives is operating properly.

2. Linear Test: Tests to see if every single spot (called a “location”) on the hard disk can be located and if data can be read.

3. Butterfly Test: Tests how quickly the read/write heads can alternate between a spot at the beginning of the hard disk and a spot at the end.

4. Random Test: Tests to make sure the read/write heads can alternate between random spots, with no pattern to guide the heads.

· Floppy Disk: For this test, first select a floppy drive to test, either the A: drive or (Drive 0) or the B: drive (Drive 1). Next, get a “scratch disk” (a practice disk containing no valuable information) from the equipment cart. CheckIt will then ask you to insert a disk into the floppy drive to test out the drive. At this time, it is EXTREMELY IMPORTANT that you TAKE OUT THE CHECKIT DISK and INSERT THE SCRATCH DISK. (If you run this test using the CheckIt disk, the computer will erase all of the information and programs on the CheckIt disk.) To begin the test, press Y and the Enter key.

· Serial Ports: Before you can run this test, you need to get a “serial loopback connector” from the equipment cart. Next, begin by choosing “COM1” from the test menu. Then, connect the loopback connector to the serial port, press Y and the enter key, and the test will begin. Some computers may have more than one serial port, and if yours does, then you should check out each port, individually.

· Parallel Ports: Before you can run this test, you need to get a “parallel loopback connector” from the equipment cart. Next begin by choosing “LPT1” from the test menu. Then, connect loopback connector to the parallel port, press Y and the Enter key, and the test will begin. Some computers may have more than one parallel port, and if yours does, then you should check each port, individually.

· Video Tests: This test involves several phases. The first few phases check the video memory (a special type of memory that is on the video care and is separate from the regular memory) and will give you error messages if the memory fails at all. The remaining tests put patterns on the screen to test color, brightness, contrast, and other video characteristics. All you have to do during these tests is look at the screen and make sure that the picture looks like what the computer says it should look like. At the end, the program will give you a list of which video tests passed and which ones failed.

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Attachment 8– Class Four

ScanDisk

Your hard drive is probably the single most important piece of equipment in your computer. Besides having command over your valuable data, it is because of the hard drive we are able to run modern software at all! But, for all of their importance, few of us perform the maintenance they need. ScanDisk is a utility that can remedy this situation.

What is ScanDisk?

ScanDisk is a software utility included with Microsoft's DOS operating system since its 6.2 release and included as a System Tool in Windows® '95. The utility "scans" a drive's integrity, checking both the file structure and the media surface. Basically, it verifies the accuracy of the hard drive's "table of contents" (called the File Allocation Table or FAT) and makes sure the hard drive's disk surfaces are suitable to reliably hold data (it will mark suspicious areas as being "bad"). On the occasion it does find a bad area (a cluster), the program will attempt to salvage the data saved there. The most common errors encountered are "lost clusters" or "cross-linked files". Unfortunately, the chances of recovered data being meaningful is low (sometimes text files can be pieced back together), but at least by deleting the recovered data, you can free up otherwise "used" disk space. When run on a regular basis, ScanDisk can repair many of the errors it finds, and prevent some complications from compounding.

DOS 6.2/Windows 3.1x Systems

At a DOS prompt, type SCANDISK. This process has two parts. The first checks files structure, the second completes the surface scan. You will have an opportunity to complete part one and skip part two, or allow for a full scan.

Note: If you want to check a floppy or any other removable media type, include its drive designation in the command (i.e. SCANDISK A: or SCANDISK B:).

Windows '95

The Windows '95 version of ScanDisk is quite automated. You will be able to access it directly from within Windows under Programs |Accessories | System Tools. Although it can run "in the background," it is suggested that you close all applications before starting the ScanDisk process. You can scan any drive on your system with either a quick check or a full surface scan or both.

ScanDisk is preventative medicine. Once a file has become corrupted, "Composer error, cannot read from drive c:” its hands are tied. You'll need a more powerful utility or the resolve to recreate the job you just lost. You should use ScanDisk regularly, Checking File Structure once a week and completing a full surface scan perhaps once a month. Either way, you'll be on your way to a healthier hard drive!

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Attachment 5- Class Three

How to Run CMOS/BIOS Setup Program:

When you turn on your computer, it first performs a Power-On Self Test (POST), which includes checking how much memory there is and whether this memory is in working condition. The test then checks other hardware to make sure all of the parts work correctly. Specifically, the test examines the kind of floppy disk drive, hard disk, and video card located inside the computer.

How does CMOS remember key information when the computer is turned off and not receiving any electricity? There is a small battery inside for this. The battery also keeps the computer's internal clock going: that's why your computer should always know the correct date and time. If your computer does not show the correct date and time, that's a good sign that the battery is low or dead. (If the time is about right, but the date is way wrong, it may just need your help to enter the new millennium - set it to 2001!)

Whenever the battery has problems or the hardware in the computer changes, you should run CMOS/BIOS Setup Program and check the information stored in CMOS to make sure it correctly documents all of the hardware currently inside the computer. Some computers check these settings automatically (or "auto-detect"), but the ability to check automatically depends on what type of setup program the computer uses. (If the battery needs replacing, the computer cannot be set up successfully until that is taken care of.)

The CMOS/BIOS Setup Program is already installed on your computer. All you have to do to run this program is press a certain key or group of keys while the computer is booting up.

Exactly what key should you press? It’s often a different key for different computers, and there’s usually no way to tell before you turn the computer on. If you look carefully, it will probably tell you what key (s) to press to get into the setup program. Typically, you just have to try a few common keys and see which one works.

Common Keys and Groups of Keys to try:

· Press the DELETE (Del) key

· Press the F2 key

· Press the CONTROL (Ctrl) key + ALT key + “S” key, all at the same time

· Press the CONTROL (Ctrl) key + ALT key + ESC key, all at the same time

· Press the F10 key (for Compaq Computers)

· Some Compaqs require booting from a floppy with their setup utilities.

Workplan

[For a copy of the Work Plan and related attachments in Word Document format click here]

Congratulations! You are ready for your next computer!

Attachment 14– All Classes

Disk Drive

Floppy Disk

Hard (Drive) Disk

Partition