The following options are available to avoid extension conflicts while using Signalyze:

1. disable all extensions while using Signalyze
2. use an extension manager
3. manually disable unnecessary extensions
4. manually change extension loading order

1. Disable all extensions while using Signalyze - top

Hold down the Shift key during Startup (when you start up your Macintosh) or during Restart. Wait until you see the "Extensions disabled" message, and then you can let go of the Shift key. All Extensions, Control Panels, and other System extensions will be disabled, leaving more memory for your program.

However, if you need Virtual Memory or RAM Doubler to run Signalyze, or if you are inputting/exporting signals and your hardware requires an extension (a Control Panel, an Extension, or other System extension), this is not an option. Disabling all extensions will disable these as well.

2. Use an extension manager - top

Extension Manager (part of the Mac System software from 7.5 and up) - top

Extension Manager, a Control Panel/Extension combination, has been included in the System software beginning with System 7.5. When you hold down the space bar during Startup or Restart, you are presented with a list of extensions. Check only those extensions which are necessary and close the window. The computer will install only the ones that are checked.

Note: System 7.6 is recommended over 7.5.x because of how much more stable it is. If you are still running 7.5, make sure you at least use the 7.5 update 2 available from the Apple updater archives.

Conflict Catcher (US$69) - top

Conflict Catcher from Casady & Green is the premier extension management utility, according to all of the Mac world authorities. It lets you control which extensions are loaded during Startup, provides help troubleshooting conflicts when they happen, and can produce a detailed report on your machine. It will automatically change the order that the extension load if it senses a conflict (see the note on loading order at the end of this file), and now gives detailed information on some 5300 files that might be found in your system folder.

Note: Users of OS 8 will need to purchase or update to Conflict Catcher 8.

Extension Overload (US$29) - top

Extension Overload gives you detailed information about what's installed on your machine. Lets you enable/disable items, plus other goodies like background info on how your Mac works plus tips on making your Mac faster. With the other tips & info it contains, it is an excellent alternative to Conflict Catcher.

An excellent feature is that the Extension Overload database is available via the web at its home page.

TechTool Pro 3 (US$97.98) - top

TechTool Pro 3 from MicroMat Inc. adds extension management capabilities and virus protection to its ability to thoroughly check out your hardware, memory, disks, files, and network problems--a highly acclaimed utility. (TechTool Lite, the free introductory version, is free, but lacks conflict management and virus detection capabilities.)

Startup Manager (no longer in development)

Startup Manager, a conflict catcher and an extension management utility for the Mac (not to be confused with StartUp Manager, its Windows counterpart), was part of the Now Utilities package from Now Software. It is generally not OS 8 compatible, but is an excellent choice if you are still running System 7. Contains many other great improvements to the System 7 Finder. A web search may turn up an older copy of the Mac Startup Manager extension.

The current incarnation of Now Utilities, a bundle of 4 utilities called Action Utilities from Power On Software, no longer supports extension management.

All of the above let you define sets of extensions so that you can control which extensions are loaded at Startup.

3. Manually disable unnecessary extensions - top

You can also disable all unnecessary extensions by moving extensions out of the System Folder and then restarting. While this is more work, and you will have to restart the machine every time you change your setup, it will prevent conflicts and does not cost anything except a little time.

You can create a new folder--next to your System Folder is a good place--and drag any Extensions, Control Panels, and other System extensions you want to disable out of your System Folder and into the new folder.

You can create a separate folder for each set of extensions for convenience. For example, if you have a CD-ROM player that you don't use when you are using Signalyze, name one folder 'CD-ROM'. When you want to disable your CD-ROM's extensions, drag them all (Extensions, Control Panels, Fonts, and System extensions) into the CD-ROM folder and restart. When you want to run the CD player again, open the CD-ROM folder, Select All (Edit menu), drag everything onto the System Folder icon (not the System Folder window), and restart. [With System 7 and OS 8, it's important to drag them onto a closed System Folder so that the System will put them into the correct folder--Extensions into the Extension folder, Control Panels into the Control Panel folder, etc.]

If you are really short on memory, most of the standard Apple Control Panels (Color, General Controls, Keyboard, Labels, Map, Memory, Mouse, Numbers, Startup Disk, Text, Views) do not have to be in the System Folder to work properly. These Control Panels change the settings of the Macintosh's memory chips; these settings are preserved by your Macintosh's battery. Moving these out of your System Folder will save you about 215K of System memory. (Some Control Panels do need to be stored in the System Folder for certain hardware and System version combinations; to find out about your setup, move them out of the System Folder, restart, and then try to open them by double-clicking on them. The System will tell you if they need to be stored in the System Folder or not.)

Even if you use an extension management utility, you can still keep less-often used extensions in a folder close to your System Folder. That way you can locate them easily when you do need them, but you will not have to worry about them when you are using your extension manager. This is a good place for Extensions for printers that you usually do not print from, Fonts you rarely use, etc.

If you are using a System version before 7.5:

Rebuilding the desktop when you are through moving things is a very good idea (the desktop keeps track of icons, open windows, etc.). This should be done on a regular basis even if you don't move things (not necessary with 7.5 and later):

• Hold down the Option and Command (Apple) keys while restarting your machine.
• Click 'Ok' when the dialog asks you if you really want to rebuild the desktop.

If you want to save the comments in the Information windows, Conflict Catcher, Norton Utilities, Now Utilities, and many others will give you this option.

If you are still having problems with crashes even though you are only using the extensions that you 'absolutely have to have', then you can still try to:

4. Manually change extension loading order - top

Sometimes changing the order that your extensions load into the Macintosh's memory will help avoid conflicts. This can be done by relocating the suspect extensions within the System Folder. Conflict Catcher (and probably other utilities) will automatically reorder files if it senses a conflict, but you can do it by hand as well if you want to take the time.

First you need to determine which extension is causing the problem. If one of your extensions is causing a crash during Startup, you can find out which one is causing the problem by watching the icons appear one-by-one on your screen during Startup. The last icon to appear before the machine freezes is usually the one causing the problem.

If you are getting crashes when using a program (such as Signalyze), it may be impossible to tell which extension is actually causing the problem. You may be lucky and get clues; for instance, if Signalyze crashes every time you try to print, then your version of SuperLaserSpoolª may be causing the problem. But even if you don't have a clue you can still find out which extension is causing the problem by doing your own detective work: move all of the System extensions out of your System Folder, Restart, and then add them back in one-at-a-time or in small groups. Remember to drop their icons onto a closed System Folder, not onto the open System Folder window or into the Extensions folder directly.

Moving them back in one-by-one is the best, but it takes the most time. To save time you can 'half-split': move half of them back in, Restart, and try to cause the program to crash the same way it did before. If you can't make the program crash again, then a problem extension is in the group left over. Add in half of them, Restart, and try to cause the crash again. Likewise, if the program crashes after you move the first group of extensions back into the System Folder, then a problem extension is in the first group. Move them all back out again, Restart, and then move half of the first group back in again. (Remember to Restart the Macintosh every time you make a change to the System Folder for that change to take effect.) Keep doing this until you have found the problem extension. You can then decide whether to throw it away or to change its loading order.

If you want to change the order that it loads, then you can change its location within the System Folder.

The following is the order that System 7 and up loads the contents of the System Folder:

• the System suitcase and all files in it
• Extensions folder items (loaded in alphabetical order)
• Control Panels folder items (loaded in alphabetical order)
• other System extensions in the System Folder (loaded in alphabetical order)

In System 6, all extensions are loaded in alphabetical order as they occur within the System Folder.

As an example, the Adobe Type Managerª extension '~ATM' is the last system extension to load. It is not marked as a Control Panel, Font, Extension, or Desk Accessory, so Systems 7 and up do not put it in a folder within the System Folder; it goes at the same directory level as the System suitcase. The tilde ('~') forces it to go at the bottom of the alphabetical list, so it is loaded last.

You can move Extensions into the Control Panels folder and vice versa to change their loading order. You can also move extensions to the same directory level as the System suitcase and use tildes ('~') to change their loading order. A space in front of the name sends it to the top of the list, a tilde ('~') sends it to the bottom of the list, two tildes ('~~') comes after one tilde, etc. (choose the View>by Name option to see what order they are listed in).