Review of Day 2

Adding New/Upgrading Old Components

• Microcomputer Resources
• Device Drivers
• Plug and Play
• Device Conflicts

• DOS/Windows 3.x
• Windows 95, Windows 98, Windows Me
• Windows NT, Windows 2000, Windows XP

• Fixing Start-up Problems
• Keyboard Problems
• Mouse Problems
• Monitor Problems
• Handling Viruses

Microcomputer Needs Analysis - Applications, Components

Computer Hardware

• System Unit - case, power supply, motherboard, ports
• Motherboard
• Bus Structure - expansion slots
• ISA - Industry Standard Architecture
• PCI - Peripheral Connection Interface
• PC Card (PCMCIA) - Laptops
• Ports
• Serial (COM1, COM2) - Mouse, Modem (115kbits/s)
• Parallel (LPT1, LPT2) - Printers, Backup (115kBytes/s)
• SCSI - Small Computer System Interface (5MBytes/s)
• USB (Universal Serial Bus) (1.5MBytes/s)
• USB 2.0 (60MBytes/s)
• IEEE 1394 (Firewireä Apple Computer) (50MBytes/s)
• CPU (Central Processing Unit)
• Celeron
• Pentium III
• Pentium III Xeon
• Pentium 4
• Xeon
• Itanium
• Memory
• RAM - check documentation for the type required
• Cache - faster memory for use by the CPU
• Disk Drives
• Hard Drives
• Plug into IDE (EIDE) or SCSI Controller
• One Physical Drive can be Partitioned into Multiple Logical Drives
• Different Partition Types
• FAT16 - DOS, Windows 3.1x/95/98/Me/NT/2000/XP
• Maximum Partition Size 2.1G
• FAT32 - Windows 95 R2, Windows 98/Me/2000/XP
• Supports Partitions into the Terabytes
• NTFS - Windows NT/2000/XP
• Graphics Card
• Various Bus Structures - check your documentation
• Resolution in Pixels
• Video Memory - 1MB, 2MB, 4MB, 8MB
• Determines Display Resolution and Colors
• Memory Required = Width x Height x Color Depth

Adding New/Upgrading Old Components

• Microcomputer Resources - Critical and Limited
• Memory Addresses accessible by the CPU
• Limited by type of CPU
• Limited by the Operating System
• Input/Output (I/O) Port Addresses (Base Address)
• Used to move information between the CPU and other devices
• 64K Byte-Wide Locations

• Interrupt Request Lines (IRQs)
• Allow external hardware to get attention of the CPU
• Early PC’s allowed 8 hardware interrupts
• Current systems have 16 (15 can typically be used)
• IRQ 2 - "Cascade Interrupt" - used to collect 8 other interrupts
• ISA cards normally cannot share an IRQ
• PCI cards normally can share an IRQ

• Direct Memory Access (DMA) Channels

• Allow data to flow without direct CPU intervention
• DMA Controller (Secondary Microprocessor) accepts a command from the CPU to move data
• From one place in memory to another
• To or from an I/O port
• Used by devices needing many-byte transfers
• Sound cards
• Scanners
• Some disk drives
• USB

• Device Drivers
• Interface between hardware device and operating system
• Interrupt Service Routines - run when an interrupt occurs
• Software - can be upgraded when original is buggy
• Check manufacturer’s web page!
• Plug and Play (PnP) - Windows95/98, Windows 2000/XP
• Meant to Make Microcomputers Auto-Configuring
• May Conflict with Legacy (pre-PnP) Devices
• Resources used by legacy devices can be "reserved" so those resources will not be used by PnP devices

• Device Conflicts
• Two Devices Using the Same Resources
• Check Resource Utilization to Find the Problem
• MSD - Microsoft Diagnostics - DOS/Windows 3.x
• Device Manager - Windows 95/98/Me/XP
• WinMSD - Windows NT/2000

Operating Systems

• DOS/Windows 3.x (3.0, 3.1, 3.11)
• Windows 3.x Runs on Top of DOS, Not Stand-alone
• Memory Management
• Most Programs Expect to Load in First 640K
• Memory Managers - load pieces of DOS, Windows, and device drivers into memory above 640K - (HIMEM.SYS, EMM386.SYS, QEMM, …)
• Windows Swap File - allows multiple programs to be loaded at once
• Device Drivers - DOS, Windows, or Both
• Configuration Settings in ".INI" Files (WIN.INI, SYSTEM.INI, MSOFFICE.INI, …)
• Windows 95, Windows 98, Windows Me
• Windows 9x is the Operating System - DOS Window
• Memory Management
• Managed by Operating System
• Windows Swap File - managed automatically
• Device Drivers - primarily Windows 9x, some DOS
• Configuration Settings in Registry - REGEDIT -
• Back up Registry before editing it!
• Windows NT, Windows 2000, Windows XP (client versions; server versions covered later)
• Windows NT/2000/XP is the Operating System - many DOS applications won’t run under NT/2000/XP!
• Memory Management
• Managed by Operating System
• Windows Swap File - managed automatically
• Device Drivers - NT/2000/XP specific
• Configuration Settings in Registry - REGEDIT -
• Back up Registry before editing it!

• Fixing Start-up Problems
• System Won’t Start
• Is it Plugged In? - Cleaning people …
• Is it Hung? - If the power switch doesn’t seem to be doing anything, unplug the system, wait a few seconds, and plug it back in. Try switch again.
• "Non-system disk or disk error" - remove floppy from drive and press any key to continue
• Repeated Beeping - check that nothing is on the keyboard
• CMOS Errors - (e.g., drive type unrecognized, system configuration differs…, etc.) - go into Setup (usually by pressing some key as the system is starting) and check the settings; if they wrong, the CMOS battery could be dead.
• "Bad or Missing command interpreter" - someone deleted COMMAND.COM; boot with a bootable floppy (e.g., your "Emergency Startup Disk" that you made when the system was new) and copy COMMAND.COM from it
• Keyboard Problems
• Keyboard Doesn’t Work
• Check Connections - mouse port and keyboard port appear identical on newer systems…
• Check Pins in Plug - if the plug was forced onto the port, one or more pins may have been bent back
• Incorrect Characters Appear
• Is the keyboard "Programmable"? - if so, check the documentation to reset it
• Computer is Beeping and Keyboard Doesn’t Work
• Check that nothing is holding down a key
• Typing Replaces Existing Text
• Press the Insert key to get out of Overtype mode and back to Insert mode.
• Check documentation for application in use
• Mouse Problems
• Mouse Doesn’t Work
• Check Connections - mouse port and keyboard port appear identical on newer systems…
• Check Pins in Plug - if the plug was forced onto the port, one or more pins may have been bent back
• Check if a Mouse Driver is Installed
• Mouse Works Erratically
• Clean it! - the ball underneath it can be removed and cleaned; internal rollers can then be cleaned
• Check Device Driver Settings
• Tracking - could be too fast or too slow making the mouse hard to control
• Check Double-Click Speed - you could be clicking too fast or too slowly
• Mouse Stops Working After a Modem is Installed
• Check the Resource Settings!
• Both could be using the same COM port
• Both could be using the same interrupt (IRQ)

• Monitor Problems

• Monitor Turned on, but Nothing Displayed
• Check connections to the computer
• Turn up Brightness and Contrast
• Check if the computer or monitor are asleep
• Press a key or jiggle the mouse
• Computer could be hung; turn it off and then back on (if power switch doesn’t seem to do anything, unplug it)
• Handling Viruses
• Run a Virus Checker - An Up-to-Date One!
• Every time the system is started
• Some can be set to scan every inserted diskette
• Removing a Virus
• Select the Clean Option of the Virus Checker
• If You Still Have a Virus…
• Contact the Virus Software Publisher for Assistance
• In extreme cases, the hard drive may need to be reformatted