Apple powerbook g4 manual Ergonomics

Page 102

Ergonomics

Keyboard and trackpad

When you use the keyboard and trackpad, your shoulders should be relaxed. Your upper arm and forearm should form an angle that is slightly greater than a right angle, with your wrist and hand in roughly a straight line.

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Use a light touch when typing or using the trackpad and keep your hands and fingers relaxed. Avoid rolling your thumbs under your palms.

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Change hand positions often to avoid fatigue. Some computer users may develop discomfort in their hands, wrists, or arms after intensive work without breaks. If you begin to develop chronic pain or discomfort in your hands, wrists, or arms, consult a qualified health specialist.

Chair

An adjustable chair that provides firm, comfortable support is best. Adjust the height of the chair so your thighs are horizontal and your feet flat on the floor. The back of the chair should support your lower back (lumbar region). Follow the manufacturer’s instructions for adjusting the backrest to fit your body properly.

You may have to raise your chair so your forearms and hands are at the proper angle to the keyboard. If this makes it impossible to rest your feet flat on the floor, you can use a footrest with adjustable height and tilt to make up for any gap between the floor and your feet. Or you may lower the desktop to eliminate the need for a footrest. Another option is to use a desk with a keyboard tray that’s lower than the regular work surface.

102Appendix B

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Contents Getting Started Apple Computer, Inc Apple Computer, Inc. All rights reservedContents Battery Appendix B Care, Use, and Safety Information Page Getting Started Plug the A/C plug on the power adapter into an outlet Connecting the Internal ModemPlugging In the Computer Opening the Display Problems Turning the Computer On? Turning the Computer OnTips for Using the Trackpad Moving Items on the ScreenAdjusting the Internal Display Adjusting the BrightnessMac OS 9, click the Resolution icon in the Control Strip Adjusting the Display ResolutionResolutions Supported by the Built-In Display Where to Go From Here Calibrating Your Battery for Best PerformanceIf you would like additional information, see the following What to Do When You Are Finished Working Put Your PowerBook to SleepShut Down Your PowerBook Page Getting to Know Your Computer If You Are New to the MacBasic Features of Your PowerBook Press and hold this key to activate the function keys F1-F12 Additional Features of Your PowerBook Connect a standard phone line directly to the internal modem Inside Your PowerBook Removable hard disk About Mac OS DockTips and Tricks What You Can DoTo Get Started To Learn MoreITools-Free Internet Services for Mac Users ICardsUpload pictures to your iDisk to create custom iCards Sherlock 2-Your Internet Search Detective Connect to the Internet Open Sherlock Macintosh Products Guide Apple.com-Your Starting Place on the World Wide WebMac OS QuickTime-Audio and Video on the Internet What You Can Do IMovie 2-Create and Edit Your Own Digital Movies ShelfShare your desktop iMovie with your friends and family ITunes-Digital Music For Your Mac New Playlist button Visuals buttonConnect your PowerBook to your stereo system Update software Adjust your Software Update schedule Multiple Users-Turn One Mac Into Many HomeCreate a new user Keeping your computer secureMac Help-Answers to All Your Macintosh Questions Using Your Computer Using USB Devices USB Devices and Battery PowerUniversal Serial Bus USB Using Multiple USB Devices at the Same Time For More Information on USBFireWire Your PowerBookUsing FireWire Devices FireWire Target Disk Mode Power adapterFireWire Devices and Battery Power For More Information on FireWirePC Cards Inserting and Ejecting a PC CardFor More Information on PC Cards AirPort Wireless Internet and Networking How AirPort Provides Wireless Internet AccessFor More Information on AirPort For More Information on Using Ethernet Ethernet 10/100/1000Base-TInfrared IrDA Making an Infrared ConnectionFor More Information on Infrared External Video Support VGA and S-Video Connecting an External Monitor Using Your PowerBook With the Display ClosedTo connect a device to the TV out port Connecting a Television, VCR, or Other Video DeviceFor More Information on Using an External Monitor or TV Mac OS X, use the Displays pane of System PreferencesBattery To remove the batteryRemoving and Replacing the Battery Calibrating a New Battery for Best Performance Mac OS X, use the battery icon in the menu barCharging a Battery Swapping Batteries While the Computer Is in SleepBattery-Conservation Tips For More Information on Your PowerBook BatteryDVD-ROM Drive Inserting a CD or DVD DiscPlaying DVD Discs Mac OS 9, use the Resolution portion of the Control StripEjecting a Disc For More Information on Your DVD DriveOptional CD-RW Drive Inserting a CD DiscUsing the Standard Function Keys Keyboard Controls and Programmable Function KeysAssigning Programmable Function Keys Using the Embedded Numeric Keypad For More Information on Keyboard ControlsSecurity Slot and Keyboard Lock For More Information on Security OptionsPage Working With Your Operating System Using Classic in Mac OS Information About Software and Mac OSSwitching Between Operating Systems Need Help? Installing Additional Memory Working Inside Your ComputerInstalling Additional RAM Working Inside Your Computer Chapter Locate the upper RAM expansion slot Page Working Inside Your Computer Mac OS Making Sure Your Computer Recognizes the New MemoryWorking Inside Your Computer Removing the Internal Hard Disk Working Inside Your Computer Chapter Disconnect the connector cable from the logic board Replacing the Hard Disk and Bottom Case Mylar sheath Connect the hard disk connector cable to the logic board Replace the battery and turn the computer over Optical drive slot Installing an AirPort Card Connect the AirPort Card to the end of the antenna cable Troubleshooting Information in This ChapterProblems That Prevent You From Using Your Computer Troubleshooting Insert the first software restore CD into your drive Restoring Your Computer SoftwareOther Problems Locating Your Product Serial NumberPage Specifications Apple System ProfilerModem speed 56 kilobits per second Kbps PowerBook SpecificationsVideo memory 16 MB DDR Sdram Output DC 14.4 Capacity 3840 milliampere-hours mAhSpecifications External S-Video or Composite Television PAL Storing Your PowerBook Cleaning Your PowerBookCarrying Your PowerBook Cleaning Your PowerBook DisplayConnecting a Phone Line to the Internal Modem Safety Instructions for Setting Up and Using Your ComputerPlugging In the Power Adapter Using Your PowerBookGeneral Safety Instructions Ergonomics External mouse Wavelength 790 nm Power out of objective lens 3.3 mW