This article contains the Read Me document for the PowerBook 3400. You may want to print this document to keep with the user's manual for your PowerBook.

Important Information

Important Information About Updating Your System Software

The system software on your computer and on the PowerBook 3400 CD are specially designed to work with Macintosh PowerBook 3400 series computers. In some instances, another version of Macintosh system software may not work with your PowerBook. Some specific software versions that do not work with your computer are listed below.

• Version 7.5.5 or an earlier version (with a lower number) is not compatible with PowerBook 3400 series computers.
• Version 7.6 , general release, is not compatible with your PowerBook. (The system software installed on your computer also has the version number 7.6, but it includes components designed only for your PowerBook model. These components are not included in the general release of System 7.6.) There is a specific release of Mac OS 7.6 that is compatible with the PowerBook 3400.

If your PowerBook is connected to an AppleTalk network by a LocalTalk connection and you are using a PC Card modem or an internal modem for data connections with a serial speed setting (between your communications program and the modem) higher than 19,200 bits per second (bps), you should turn off AppleTalk in the Chooser to avoid possible data loss during connections. This problem does not occur if your computer has an Ethernet connection.

Important Information About Using Your Computer as a Hard Disk

Be sure to use the power adapter whenever you use the PowerBook as a hard disk (SCSI disk mode). If the battery provides power when the computer is used for SCSI disk mode, the PowerBook may not display a low-power warning when the battery is low. The result could be an unexpected shutdown. If you must use SCSI disk mode without a power adapter, check the battery level first to make sure you have enough run time left to accomplish your task.

Important Information About Using the Disk Tools Floppy Disk

If you start up your PowerBook with the Disk Tools floppy disk, do not put the system to sleep (by choosing Sleep from the Special menu, closing the computerıs display, or pressing the Power key and choosing Sleep in the dialog box). The Disk Tools disk does not have all system software components needed for the computer to wake from sleep. This same advice applies to any disk or PC Card that contains a copy of the System Folder provided on the Disk Tools disk.

If you do put the computer to sleep and cannot wake the system, use the emergency restart procedure: Hold down the Command and Control keys when you press the Start key.

When the computer starts up from the Disk Tools floppy disk, the system may not recognize a PC Card that was inserted before the computer started up. If you donıt see the icon for a PC Card after the startup process is complete, eject the PC Card and insert it again.

Note : The Disk Tools floppy disk does not contain complete system software. Use this disk only as a temporary startup disk.

Important Information About Using a PlainTalk Microphone

Note : To avoid getting feedback when you use a PlainTalk microphone, be sure that the microphone is at least 1 foot away from the computer.

Note: To avoid feedback when recording with the PlainTalk microphone, be sure that the Listen option is turned off in the Monitors & Sound control panel. Follow these steps:

1. Open the Monitors & Sound control panel.

2. Click the Sound button.

3. In the Sound Recording Input section of the control panel, choose Line In from the pop-up menu.

4. Click to remove the X from the Listen box.

For best results, use the Quick Take Image Access control panel to look at images in the camera and transfer them to your Macintosh. This method is faster and more reliable than using the PhotoFlash program.

Important Information About Viewing MPEG Images

When using QuickTime to play MPEG movies with either MoviePlayer or Apple Video Player, you may want to change one or more settings to achieve optimum playback:
- set the disk cache to at least 1 megabyte (MB) in the Memory control panel;
- turn off virtual memory (VM) in the Memory control panel;
- hide the Control Strip, using the Control Strip control panel, if you cannot set the disk cache to 1 MB.

Changing the disk cache should permit optimum playback.

To reset the disk cache and turn off VM, follow these steps:

1. Open the Memory control panel.

2. Use the arrows at the upper-right section of the control panel to set the disk cache to 1 MB or more.

3. Click the Off button in the Virtual Memory section of the control panel.

4. Restart the computer.

1. Open the Control Strip control panel.

2. Click the Hide button.

When the IrDA method of infrared (IR) communication is selected in the AppleTalk control panel and AppleTalk is on, the computer will not go into sleep automatically.

Important Information About Using an External AppleVision Monitor

• If you want to use an AppleVision monitor with your PowerBook, be sure to install the software that came with the monitor on your computer. Follow the instructions that came with the monitor for installation details.
• When connecting an AppleVision monitor to the PowerBook, be sure to connect the monitor's ADB cable to the ADB port (on the left side of the computer, near the back panel). This connection is required by the AppleVision software.

Using an External Monitor

Monitors

Sound (for using the sound capabilities built into an AppleVision monitor)

To set up or change most settings for an external monitor, you use the Monitors & Sound control panel.

Note : You may see two Guide files that contain information about monitors and sound. One of these is Mac OS Guide; it contains all the instructions related to an AppleVision monitor and your PowerBook. The second Guide is available when the Monitors & Sound control panel is open; it is Monitors & Sound Guide. This Guide contains only the instructions for using the Monitors & Sound control panel. You can switch back to Mac OS Guide by clicking the desktop and choosing Mac OS Guide from the Guide menu. (Mac OS Guide contains the same instructions as Monitors & Sound Guide, plus general instructions for using an external monitor and all information about using other parts of the system software.

Some special features of an AppleVision monitor may not be covered in Mac OS Guide or Monitors & Sound Guide. For information on using the Geometry, Color, and Monitor Sound settings for an AppleVision monitor, refer to the manual that came with your monitor. (Clicking the Color, Geometry, or Monitor Sound button of Mac OS Guide or Monitors & Sound Guide will display information, but this information may not be complete or accurate for an AppleVision monitor. The monitor's manual will have the correct information.)

The Monitors & Sound control panel may occasionally have "cosmetic" problems when displaying settings for an AppleVision monitor. These problems will be corrected in a future version of the control panel.

Mac OS Guide and Monitors & Sound Guide

When you access a sound or monitor topic in Mac OS Guide, the name in the main Guide window will change to Monitors & Sound Guide. When you access another topic, the name changes back to Mac OS Guide.

Occasionally the name displayed at the top of the main window of Mac OS Guide (where topics, index terms, and Look For phrases appear) may change when you return to this window from the step-by-step instructions. If this occurs, the content of Mac OS Guide does not change; the window is simply displaying the incorrect graphics for the Guide name. You can continue to use any of the items in Mac OS Guide even if a different name appears in the main window.

Note Pad Is Installed

Another Read Me document may indicate that the Note Pad software (in the Apple menu) is not installed. The Note Pad is installed on your PowerBook.

FreePPP

If you plan to connect to the Internet via PPP, use the Open Transport/PPP (OT/PPP) software that is already installed on your PowerBook computer. FreePPP is currently incompatible with the installed America Online (AOL) link extension that is also installed on your computer. America Online is working on an update to the AOL link extension. See the Connecting to the Internet topic area of Mac OS Guide for instructions on using the OT/PPP software.

Tips

Backing Up the System Software on Your Computer's Hard Disk

It's a good idea to make a backup copy of the System Folder and other system software that is installed on the hard disk of your PowerBook. You can use the System Backup folder, located inside the Apple Extras folder on your hard disk, for this purpose. The programs and files inside the System Backup folder allow you to create floppy disks of the system software and to reinstall the system software from special files (disk images). See the file named "System Backup Read Me" in the System Backup folder for instructions.

Reinstalling System Software from the System Backup Folder or the PowerBook 3400 CD

If you experience problems with your System Folder or other system software on your computer's hard disk, you can reinstall the system software from three sources:

• Using the Installer program in the Launcher control panel. (This program uses files in the System Backup folder, inside the Apple Extras folder, on your hard disk. See "About System Backup" for instructions.)
• Using files on the PowerBook 3400 CD that came with your computer (if you have a CD-ROM drive available). See the file "CD-Important Information" on the CD for instructions. (You can use the CD to restore system software only or all the software that was installed on your hard disk at the factory.)
• Using floppy disks you created using files inside the System Backup folder on your hard disk. See the file "About System Backup" for instructions.

1. Open the Launcher control panel (in the Control Panels folder, in the Apple menu).

2. Click Service/Support at the top of the Launcher window.

3. Click Install System Software to reinstall core system software, or click Make System Floppies to make a backup set of floppy disks for core system software.