As with the control panels section, below and in the previous two chapters are descriptions of nearly every Apple Extension ever released. If you're curious what the different extensions do, here's your source. If you're interested in whether or not you need various INITs, use the descriptions below to decide whether or not you want/need them. Most are from Apple; however a few are things that are so universal that I included them here (for most non-Apple extensions, check out the "Third-Party Extensions" chapter).
ΓÇó Quadra AV Monitors Extension (v7.5): same as "Quadra Monitors Extension," below, only for Quadra AV- and Centris AV-series computers, so it includes the AV video display options.
ΓÇó Quadra Monitors Extension (v7.5): allows the Monitors control panel on Quadra- and Centris-series computers to reflect the capabilities of the built-in video. Provides information on the resolution and scan rate for an attached monitor. If you remove this extension, the monitor will work fine; however, the extra "options" such as gamma control will be inoperable.
ΓÇó QuickDraw GX (v1.1.6): provides support for advanced graphics and typographic services under the Mac OS. On pre-OS 8 systems, if this extension is installed, you must also have GX-compatible printer drivers. Under these systems, if you have this extension installed, non-GX drivers will not even show up in the Chooser. If you are experiencing this problem, put the QuickDraw GX file in the "Extensions (Disabled)" folder, or in the trash, and restart your computer. The Chooser should then show all of your normal printer drivers. NOTE: Although QuickDraw GX printing is no longer supported under OS 8, the advance graphics and typography capabilities of QuickDraw GX are still supported via the GXGraphics extension, and will eventually be rolled into the standard Mac QuickDraw environment.
ΓÇó Record Button: provides support for the "record" button on the Apple Adjustable Keyboard. Now incorporated into the AV and PowerMac series' ROMs.
ΓÇó Scanner (v3.0): driver used by all "Apple-compatible" scanners (basically, all Apple scanners and any third-party scanners which were designed to use the Apple driver).
ΓÇó Scripting Additions: actually a folder within the Extensions folder. The additions contained in the folder enhance the language of the AppleScript system by adding special features such as the time of day, day of the week, or date. When installed, AppleScript behaves as if these additions are part of the standard language. These items are only required when using a script that incorporates them.
ΓÇó SCSI Manager 4.3 / SCSI Manager 4.3.1: the new SCSI Manager (4.3.x) system added several new features (such as SCSI 2 compliance, concurrent asynchronous I/O, and disconnect and reconnect) to the Mac's SCSI architecture. There is a lot of conflicting information to be found about these extensions. Even Apple's own Tech Info Library gives contradictory explanations. The following is the best summary I can offer (and it is admittedly confusing): Version 4.3 is part of the ROMs on all Power Macintosh and Quadra AV computers, and is installed as a separate extension by the System 7.5 CD, even on these machines which already have it in ROM. It is incorporated into the System under System 7.5.3 and later. So anyone running System 7.5.3 or later should not have any version of this extension installed. The new (4.3/4.3.1) SCSI system is supposedly supported on all PowerPC and 68040 Macs, except for the 630 series and 68040 PowerBooks (including Duos). If your computer doesn't require this extension, you should probably delete it. (In yet another source of confusion, one Apple article claims that having the extension installed when not needed can cause serious problems, while another said that it would not do any harm. This is clearly a situation where too many people at Apple are trying to explain something that none of them knows enough about!) The remaining info is only for people not running System 7.5.3 or later: Non-QuadraAV 68040 Macintosh computers require the SCSI Manager 4.3 extension under System 7.5, or the SCSI Manager extension under System 7.5.1. The SCSI Manager 4.3.1 extension from System 7.5 Update 1.0 contains software fixes needed only on 68040-based Macintosh computers with the PowerPC Upgrade Card. Even though Apple claims that the new SCSI system is not supported on 630-series and PowerBooks, they also say that version 4.3.1 of the extension is needed on 630 machines, the PowerBook 150, and the Quadra AV models to fix possible data corruption problems. It is also supposedly used on those computers to fix a potential crash problem with some (unspecified) external hard drives.
ΓÇó SCSI Manager Update (v1.2): previously released by Power Computing, this file is now maintained and distributed by Apple. Fixes a problem where PowerBase computers using external SCSI devices could crash at startup.
ΓÇó SCSI Update: included with the AppleShare IP 5.0 beta. Supposedly updates the SCSI Manager to allow asynchronous access on machines that don't already support it, such as 680x0 machines and early PowerMacs. The new SCSI Manager is required for products such as the Advanced Driver Toolkit from Dantz for accessing Digital Linear Tapes from within Retrospect.
ΓÇó Serial Update 406: eliminated by the 7.5 Update 2.0. Part of the Apple Personal Modem package. If used under OS 7.6, your machine will freeze at startup.
ΓÇó SerialDMA 2.0.2 [17.5/?]: first, a note on the DMA chip: a computer's processor supervises the transfer of data between memory and connected devices (such as a hard drive). This takes time away from other processor functions. PowerMacs and the AV Macs, as well as some newer PowerBooks, have what are called direct memory access (DMA) chips, which handle some or all of this data transfer processing, allowing it to pass directly from connected devices to RAM. Note that in order to use this DMA, the connected device must use a driver which was written to support DMA transfers. SerialDMA v2.0 was originally a rewrite of the serial drivers that shipped with the first AV Macs (the Centris 660AV and Quadra 840AV) and were later carried over to Apple's first line of Power Macs (6100, 7100, 8100) and their derivative models. Version 2.0.2 of SerialDMA patched some remaining bugs and added support for Apple's newer PCI Power Macs. In addition to offering greater reliability, better performance, higher baud rates, and a number of bug fixes, version 2.0.2 offered significant performance improvements on 68040-based AV Macintoshes, as well as fixes for printing problems with StyleWriters on PCI Power Macs. Under System 7.5.2, SerialDMA (both versions) had known problems on PCI Macs with the Serial Port Arbitrator extension that is included with AppleTalk Remote Access (ARA) and with the Port Juggler extension. However, Serial DMA has been incorporated into the System since System 7.5.3, and these incompatibilities have reportedly been resolved.
ΓÇó Shared Library Manager (v2.0.1) [NA]: supports loading, unloading, and sharing of object-oriented code, including all "shared library" files. Provides support for Open Transport. This extension is needed on both 680x0 Macs (for universal support) and on PowerMacs (for emulation support). NOTE: the Microsoft Word 5.1a installer and the Microsoft Office 4.2.1 installer may remove the latest version of the Shared Library Manager and replace it with an older version! NOTE: there is a confirmed conflict between the Shared Library Manager and Mathematica v3.0 and v3.0.1 where a substantial delay can occur after pressing the enter or return keys. While disabling SLM seems to alleviate the problem, it may also disable other functionality on your Mac (such as Open Transport). NOTE: In the category of "things that need SLM that you wouldn't expect," Apple's Desktop Printing Utility requires that the Shared Library Manager and (on PowerPC Macs) the Shared Library Manager PPC be installed.
ΓÇó Shared Library Manager PPC (v2.0.1) [NA]: supports loading, unloading, and sharing of native object-oriented code, including all "shared library" files. Provides PowerPC-native support for Open Transport and other libraries. Both this extension and the "Shared Library Manager" (above) are needed for OT and other shared libraries to function properly on a PowerMac, while 680x0 users only need the non-PPC version. NOTE: the Microsoft Word 5.1a installer and the Microsoft Office 4.2.1 installer may remove the latest version of the Shared Library Manager PPC and replace it with an older version! NOTE: In the category of "things that need SLM that you wouldn't expect," Apple's Desktop Printing Utility requires that the Shared Library Manager and (on PowerPC Macs) the Shared Library Manager PPC be installed.
ΓÇó Slow SCSI Extension: addresses a potential conflict between PowerBook 5300 series computers (and possibly other models such as the 190 and 1400) and slow SCSI devices (such as single-speed CD-ROM drives, Zip drives, and other PowerBooks attached via SCSI disk mode) where sometimes the PowerBook will crash and/or freeze. Not all PowerBooks will experience this problem and even PowerBooks that do will not necessarily experience it on a consistent basis (even with different units of the same make and model). The reason for this conflict is due to two peculiarities found in these PowerBooks: 1) the internal hard drives are IDE drives, and as such do not provide an "anchor" for the SCSI chain; 2) the PowerBook does not provide steady termination power to the SCSI chain. When these two factors are put together, activity on the SCSI chain can cause power along the chain to fluctuate, and thus intermittent termination; if too much fluctuation occurs, the PowerBook crashes due to SCSI termination problems. This extension actually slows down data transfer rates along the SCSI chain, dampening these fluctuations enough to avoid the problem. NOTE: You should only install this extension if you are experiencing constant freezes or crashes when transferring files with a particular SCSI device, since it will impact performance with ALL SCSI devices by 10 to 50 percent. While the slowdown may not seem significant with an external Zip drive, it will quickly become apparent if you have a 24x CD-ROM drive attached! You can use a startup manager to disable the extension when not needed.
ΓÇó SOMobjectsΓäó for MacOS (v2.0.8): see the entry under "OpenDoc" in the "Groups" section. NOTE: this extension is necessary in order for Contextual Menu plug-ins to function properly.
ΓÇó Sound Input Amplification (v1.0): adds the "microphone amplification" option to the Sound control panel, which when active amplifies sound input by +25 dB. Some microphones, such as the Apple PlainTalk microphone, produce a "line-level" signal which does not need amplification to be properly received by your computer's sound hardware. However, other microphones produce a "mic-level" signal which needs to be amplified. If you are using a microphone which produces a mic-level signal, you will need to turn microphone amplification on. NOTE: according to Apple, this extension was designed for PowerMac 7200 computers, and thus can be found in the "Apple Extras" folder on the hard drive of 7200's or on the 7200 System CD-ROM. NOTE: according to Apple, the Sound Amplification Input extension is not supported under System 7.5.3 and later. If you are running 7.5.3 or later, you should use a microphone which supplies the proper line level voltage, such as the Apple Plaintalk Microphone.
ΓÇó Sound Manager (v3.3) [0/96]: PowerMac native. Version 3.3 is installed as part of the QuickTime 3.0 package. Version 3.2.1 is no longer needed under Mac OS 8 and later, as it has been incorporated into the System file. Sound Manager 3.2, which provided asynchronous sound playback and better Power Mac performance, was incorporated into the System in System 7.5.3. For users of pre-OS 8 System software, Version 3.2.1 is available as part of the QuickTime 2.5 package, and supposedly provides even better low-memory performance and better multi-channel sound via a new sound clock component. Version 3.2 is included in the System file under System 7.5.5. NOTE: according to the Mac OS 7.6 Technical Note, Sound Manager 3.2.1 is actually built into the System file under 7.6 and the extension is no longer needed; however, that statement seems to go against all other Apple documentation on version 3.2.1. For the time being, if you are using OS 7.6 or 7.6.1, I would recommend keeping this extension until further clarification can be found. It will not cause any harm to have version 3.2.1 installed even if it has been incorporated into the System. NOTE: on a Quadra with a PowerPC card and System Software 7.5.1, you may need to update your System Software to 7.5.3 to use Sound Manager 3.2.x or later. NOTE: under pre-OS 8 systems, the QuickTime 2.5 installer will only "Easy Install" v3.2.1 if an older version is present, so be sure that you have your older Sound Manager extension present before you install, or else do a "custom" install. NOTE: on PowerBook 500 series computers which have not been upgraded to PowerPC, Sound Manager 3.2.1 prevents sound recording. If you wish to record sounds, you should disable this file and restart. When you have finished recording sounds, you should then re-enable it and restart.
ΓÇó Startup Tuner [NA]: part of the System 7.5.3 revision, fixes a problem with the Startup Disk control panel where the Mac may not startup from the selected disk. Only useful on the models for which the Revision is recommended (see Chapter 2). Not necessary under System 7.5.5 and later.
ΓÇó Stationary: not really an extension. Part of the QuickDraw GX package, this extension enables the "Stationary" paper type option in the "Page Setup..." window of compatible applications. NOTE: GX printing is not supported under OS 8 and later.
ΓÇó System 7 Tuner: part of System 7.0, this extension was part of the System Tune-Up disk. It provided better memory management for the initial release of System 7.
ΓÇó Telephone Manager Extension (v3.0): installed by Apple Telecom software, as well as the USR modem software. Allows you to use your modem and computer together as an answering machine. Also allows you to control your phone line via your computer.
ΓÇó Text Preview: when using ClarisWorks 4.0, and other compatible applications, shows previews of TEXT files in the preview window of the "open" dialog box. NOTE: The Text Preview extension conflicts with the "file preview" feature when selecting MPEG files in Open/Save dialogs. While this does not affect the ability to view MPEG files, you will not be able to preview them in Open/Save dialogs.
ΓÇó Thread Manager (v2.1.5): This file is no longer needed under Mac OS 8 and later, as it has been incorporated into the System file. Thread Manager is an addition to the Macintosh Toolbox that enables "concurrent programming" for real multitasking within an application. Supports cooperative and preemptive threads of execution at the application level, but not at the system level -- sort of the Mac's version of "multi-tasking" (although true multitasking occurs across applications and includes System operations). Version 2.1 of this extension, which is what the Finder and most applications still use, has been incorporated into the System since System 7.5. However, the installer for Apple's QuickTime MPEG Extension installs a newer version of Thread Manager (2.1.5) which is required for QT MPEG support under OS 7.6.1 and earlier. NOTE: The LaserWriter 8.4.1 and Desktop Printing 2.0.1 installers delete the newer (v2.1.5) Thread Manager extension; the various Color StyleWriter software installers actually delete it and replace it with the older v2.1! If you are planning to install the LW 8.4.1 or Color StyleWriter software, disable or remove Thread Manager 2.1.5, and then enable or replace it after the installation.
ΓÇó TokenTalk Phase 2 (v2.5.7): driver used by the Apple Token Ring card and the Network/AppleTalk control panels.
ΓÇó TokenTalk Prep (v2.5.2): provides added support for the TokenTalk Phase 2 driver.
ΓÇó Trackpad Climate Control (v1.1): reduces unexpected pointer movements caused by humidity or moisture on the trackpad. Only works on the PowerBook 190, 1400, and Duo 2300. You should not use this extension if you don't have pointer movement problems, as it could actually make the pointer less responsive. This file is no longer needed under Mac OS 8, as its functionality has been incorporated into the System file.
ΓÇó TrueType: needed by System 6.0.7 and all subsequent versions of System 6 to print TrueType fonts, as well as to display them on screen.
ΓÇó UDF Volume Access (v1.0): provides support for Universal Disk Format (specifically, it provides support for volumes recorded at the "Optical Storage Technology Association UDF 1.02" specification level). Installed by Mac OS 8.1 for support of DVDΓäó disks. NOTE: does not provide the ability to read Adaptec DirectCD discs; for this functionality, the "Adaptec UDF Volume Access" extension is needed. OS 8.1
ΓÇó Video Digitizer Update: part of the Apple MPEG Media System. Provides the software interface between the built-in video and the hardware MPEG card.
ΓÇó Video Out Default (PAL) (v11.2): used by the Apple Video Player. On the standard U.S. System, the default video-out for the Apple Video Player is NTSC. Outside of the U.S., the standard video format is PAL; this extension changes the Apple Video Player default to PAL.
ΓÇó Video Startup (v1.6/v1.7.1) [22/0]: provides support for the Apple Video Player; needed to use the AVP. NOTE: if you have differing versions of the Video Startup extension and the Apple Video Player, the Video Player will not work. NOTE: the following is a list of OS versions and the appropriate version of the Apple Video Software for it: System 7.5.3 - v1.4; System 7.6 - v1.4.2; Mac OS 8 - v1.6.3; Mac OS 8 on the PowerMac G3 - v1.7; Mac OS 8.1 - v1.7.1. NOTE: version 1.4.2 is available online at Apple SW Updates as "Video SW Install 1.5.1." NOTE: If you disable the "Video Startup" extension on a Performa 6300CD the Volume-Up button on the front of the CPU will not work. The Volume- Down continues to work. NOTE: If you are going to install System 7.5 Update 2.0 (ignore this part if you have OS 7.6 or later), first check the version number of both Video Startup and the Apple Video Player. During the installation, you may get a message that says something like "a newer version is already installed." However, chances are it really isn't, and you do need to install. If you did already have 1.4 installed, leave it. If you have a version prior to 1.4, ignore the installer's warning and install the "older" version. This is a bug in the 7.5 Update 2.0 installer. You should end up with v1.4. If not, you should go back and do a custom install of only the Apple Video Player software.
ΓÇó Voices: folder which contains voices for use by Speech/ PlainTalk/ Text-to-Speech. NOTE: Apple has made available three "high-quality" versions of the Agnes, Bruce and Victoria voice files. These voices are supposedly more lifelike and more easily understandable. However, they only function with MacinTalk Pro. If you are not running the MacinTalk Pro extension, you cannot use the high quality voices.
ΓÇó Web Sharing Extension (v1.5): supports Personal Web Sharing under Mac OS 8 and later. OS 8
ΓÇó WGS SCSI Manager Update 2.0: required for compatibility between Mac OS 8 and Workgroup Servers 7350 and 9650.
ΓÇó WindowPicker (v1.1): older "unsupported" utility which provides the ability to bring any open window to the front via a pop-up menu and/or arrow keys. Does not work with System 6.x.
ΓÇó WorldScript Power Adapter (v7.5.3): see entry in the "WorldScript" section of the "Groups" chapter.
ΓÇó ┬░AppleVision (v1.5.5): only used for support of AppleVision displays, such as the 1710AV. Previous versions (1.0.2, 1.0.4) were plagued by compatibility problems. The version number was upped to 1.5.3 and, subsequently, 1.5.5 for continuity with the entire AppleVision 1.5.3 and 1.5.5 packages (see entry under "Groups").
ΓÇó ~AudioVision: part of the AudioVision 14" monitor software package. Only needed on pre-7.5 systems.
ΓÇó ΓÇó Shutdown Items enabler: provides support for the "Shutdown Items" folder under System 7 Pro. The extra bullet in this item is actually part of the extension's name so that it will load last in the startup process.
