An operating system (OS) determines a computer’s basic behaviour, from the
way it responds to a keyboard or mouse to how it handles data over a network.
The Operating System
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  The Mac keeps system components that rarely change in Read Only Memory
(ROM) and the larger part on the startup drive. This makes the Mac easy to
upgrade — it’s a clean machine.
The system is grouped into two sets of Managers, a Toolbox of programming tools and the operating system itself, made up of hardware managers.
During startup, data from specific files in the startup disk’s System Folder is transferred into Random Access Memory (RAM). Of these, the Finder and System are most important.
System Versions
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  Each time the OS is improved a new system version is issued. This FREE Guide is
based on System 7.5.5 — the differences between this and the many other
versions of System 7 aren’t documented here!
System 8 promises a configurable interface and a multi-tasking Finder on PowerMacs or 680x0 Macs upgraded with a PowerMac logic board — but not for models with a PowerPC piggy-back processor. Duplicate application programming interfaces (APIs) will be used for current applications and System 8 applications — the latter not using the extensions in System 7. PowerPC Platform (PPCP) machines, due in mid-1997, will also be able to run Windows NT and other PowerPC-based operating systems as well as the Mac OS.
Always try to use the latest version of OS — you’ll get the best from your Mac!
You should only use an older version if:-
• You’re using an older machine that can’t accommodate the extra overheads of
memory, disk space and speed necessary for a newer system.
• You need to use an application which doesn’t work on a newer system and you
can’t get an update for the software!
All modern applications need System 6.04 or higher to work correctly.
The following list shows the oldest recommended systems for early models:-
Model System Version
Mac Plus/SE/II/IIx/IIcx/IIci/IIfx/Portable 6.05
Mac Classic/IIsi/LC 6.07
Mac LCII 6.08
All others machines should use the latest system.
The original System 7.0 works well on most older machines and uses a relatively small amount of memory. Your Apple dealer can supply System 7.0 enhancements that extra features, such as drag and drop, that are found in System 7.5.
The System Folder
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  The System Folder on the startup disk contains all the software for a complete
system. Only one System Folder can reside on a startup disk — adding more only
creates problems! An active or blessed System Folder has Mac icon on its folder.
€ A System Folder can be made inactive or unblessed by dragging the System file out of
the folder. If your System Folder lacks it’s Mac icon you may have to drag the System
file out and then put it back again!
€ The System Folder can be renamed — but this isn’t advisable.
The System Folder must contain at least the System and Finder files for normal operation. Many items in the System Folder are independent of applications but others are introduced during the installation of new software. They are usually placed within a special folder but some older applications may require these items to be ‘loose’ inside the System Folder.
√Ö Corruption of any system component can cause your Mac to fail.
Å Don’t tamper with the System Folder unless you understand it!
System Folder Items
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The following items should be found in the System Folder:-
that appear in the Ô£ø menu. Any item can be put in a folder within the Apple
Menu Items folder — if the Apple Menu Options control panel is enabled each
folder produces a submenu in the Ô£ø menu.
Aliases are dummy files that behave in the same way as an original file, folder or application. They can be put into the Apple Menu Items, Startup Items, Shutdown Items (see below) or any other folder. If you rename the original file the alias will still find it.
¬ø Only the first 50 items in the Apple Menu Items folder will appear in the Ô£ø menu.
Clipboard
  This file contains the last item that you’ve Copied or Cut. Data may be stored in an
application format as well as a standard format such as TEXT or PICT.
Information in the Clipboard file is also stored in memory to provide faster access for applications. Unfortunately some applications use a private clipboard in their own area of memory which others can’t reach. This means they have to use the Clipboard file instead, resulting in an increase in disk activity and slower performance. Further activity may occur if you use an extension to provide you with multiple clipboards.
Control Panels folder
  Contains several control panels (CPs) that configure your Mac — each panel may
also be known as a control device or cdev. Some panels contain INITs that modify
the system during startup, increasing the amount of memory used by the system.
If you remove this type of panel you’ll lose the features it provides.
Control panels that increase memory requirements include:-
Apple Menu Options Macintosh Easy Open
ATM GX MacTCP
CloseView PC Exchange
Date & Time PowerTalk Setup
Easy Access TCP/IP
General Controls WindowShade
æ Dragging a control panel out of the Control Panels folder will stop you making any
changes to settings. Any settings you’ve already made may be retained if they’re
kept in a preference file or elsewhere.
æ If you make a change to the settings of a control panel the effects may be seen
immediately — with some you must wait until it’s window’s closed. Others, such as
Memory, don’t take effect until after restart or shutdown.
Control Strip Modules folder
  Contains Control Strip modules that can be used with any Mac, providing the
Control Strip control panel is enabled.
Editors folder
  Contains part editors used by OpenDoc for data handling plus the OpenDoc folder
containing OpenDoc Shell Plug-Ins and OpenDoc Libraries folders — the latter
holds the OpenDoc application itself and associated library files.
Each OpenDoc application has its own folder inside this folder.
Extensions folder
  Contains files that add functionality to your Mac — hence the jigsaw icon. They
include printer drivers, which tailor for specific types of printer, network drivers,
for networks such as Ethernet, or communication tools for modems.
There are two types of extension — System extensions and Chooser extensions.
Many system extensions contain INITs that modify the System during startup. Nearly all extensions use some memory, although most CD access files and others are exceptions.
Extensions that increase memory requirements include:-
EM Extension Finder Scripting Extension
AppleGuide Foreign File Access
AppleScript PowerTalk Extension
Colour Picker PowerTalk Manager
ColorSync PrinterShare
File Sharing Extension QuickDraw GX
Find File Extension QuickTime
Finder
  This special application creates the Desktop and locates files with their associated
applications — any number of these can reside in memory at any one time.
´ Applications remain in memory until Quit or until your Mac runs out of memory!
The memory used by an application can be adjusted in its Get Info window.
Fonts folder
  Contains up to 128 font suitcases, each holding any number of fonts up to a
maximum of 16 M. It can also contain PostScript outline font files.
Hosts
For using the Internet with the MacTCP or TCP/IP control panels. This standard SimpleText file contains a Domain Naming System (DNS) list, as used in the absence of a name server. The TCP/IP panel looks for a similar file in the Preferences folder before using this one.
Launcher Items folder
  Contains items that appear in the Launcher window. You can remove this
folder if you don’t use the Launcher.
Note Pad
  This file contains text that appears inside the Note Pad application.
You can remove this file if you don’t use it.
Preferences folder
  Contains files storing your settings for each application and for some control
panels. The System Installer adds a number of files and folders whose function
are usually obvious. Application installers often add other further items.
Removing a preference file (it has a ‘button’ icon) can sometimes solve problems with applications — try removing Finder Preferences if you have trouble with the Finder. Having removed a file it’s often a trivial job to restore your settings in an application — but in some cases it can be more serious. In these instances it’s a good idea to keep a backup of the file so that you can restore it at a later date should it become corrupted.
Folders in the Preferences folder often provide resources that are used by an application — if you remove them you’ll lose the features they provide!
The AppleMail Letterheads folder provides a range of letterheads that can be used with the AppleMail application in conjunction with PowerTalk. The ColourSync‚Ñ¢ Profiles folder is used by the ColourSync‚Ñ¢ System Profile control panel for accurate colour matching with the devices that appear in the folder.
Internet Preferences is used by Cyberdog and other Internet applications. The Printing Preferences folder contains preferences for each type of printer you’ve used together with PICT files employed by some printers to create a watermark across a printed page.
PowerTalk Data folder
Contains data used when PowerTalk is in operation.
PrintMonitor Documents folder
  When background printing is selected in the Chooser this folder contains printer
files for documents awaiting printing. The same folder is used by the
PrintMonitor and Desktop PrintMonitor applications
Scrapbook
  Contains all the items that appear in the Scrapbook application. If you use an
alternative application you can remove this file.
Startup Items folder
  Contains any items, preferably aliases, that launch automatically immediately
after startup. The items are launched in alphabetical order.
Shutdown Items folder
  Contains items, preferably aliases, to launch prior to shutdown. The items are
launched in alphabetical order. You must choose Shut Down or Restart from the
Special menu to make them launch — Shut Down in the  menu doesn’t work!
System
  This file makes your machine work! It includes routines called ROM patches that
replace any software in ROM that’s now outdated. The System file accommodates
all models of Mac and replaces all of the enabler files used in older systems.
à Your Mac will run slowly if the System file is fragmented across the disk.
The System also stores resources that you can see when you double-click on its icon. You can move these in and out as with a folder. The resources include alert sounds (used by the Sound control panel) and keyboard resources (used by the Keyboard control panels).
Problems with the System file can cause:-
z Failure at startup
z Slow operation
z Difficulties with screen, memory, desktop or fonts
z Bombs
If your system has only been updated to System 7.5.3 this file will be accompanied by a System 7.5 Update or System 7.5.2 Update file (but not both), depending on the original version that’s been updated. These files work as a universal enabler on any model of Macintosh and provide extra features in the system. They replaced the model-specific enablers, if any, used by previous system versions. If you have correctly updated your system to System 7.5.5 these files, and earlier enablers, shouldn’t be present.
Text Encodings folder
Contains files, used by Internet applications such as Cyberdog, that accommodate the different character coding systems used in various parts of the world. These include
ISO Latin-1, Unicode and Windows Latin-1.
•Archived Type 1 Fonts• folder
Contains PostScript Type 1 font files that have been enabled for QuickDraw GX during its installation. They can be returned to the Fonts folder when GX is no longer used.
Saving Disk Space
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If you know what you’re doing you can remove System Folder files from your drive to conserve disk space or to reduce the memory used by the system.
´ Some files can’t be installed individually with the System Installer (see below) — you
must use Easy Install which adds even more files! If you remove any system file it’s
advisable to copy it onto another disk just in case it’s needed again!
To save memory only you can move unwanted files into new folders in the System Folder. For example, you can move Puzzle in Apple Menu Items into a folder called Apple Menu Items (Disabled). This labelling system should be used for any category of system file and works with an extension manager, such as ExAminer, Symbionts or Extensions Manager.
Assuming you don’t need AppleTalk, you can save memory by setting AppleTalk to Inactive in the Chooser.
The following lists show some files that can be removed to save memory:-
Control panels
AppleTalk
Close View
Colours — if working in monochrome
ColourSync Profiles
  Easy Access
File Sharing
MacTCP
Monitors — if you only have one screen
Network
PowerTalk Setup
QuickTime Settings
TCP/IP
Users & Groups
Extensions
AppleShare
CD Access files
ColorSync
Network Extension
  Printer drivers — except those that you need
Printer Share
PrinterShare GX
QuickDraw GX
QuickTime
√Ö Restart your computer after removing these files.
System Installation
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  This process transfers a System Folder, complete with necessary files, onto the
startup drive of your Mac. A System Installer application is used to select the
resources required for the features on your particular model.
When Installation is needed
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Installation is necessary when you have a:-
z New machine
z Damaged System
z Corrupted Disk
In the case of a damaged system the symptoms may include a Sad Mac icon at startup or excessive crashes with different applications or in the Finder.
Other problems, such as a flashing Happy Mac or an empty box instead of Welcome to Macintosh, may be solved by trashing Finder Preferences in the Preferences folder. Both of these symptoms can also be a result of trashing the At Ease control panel before switching your Mac off. To get rid of At Ease you must first go to its control panel, switch it off and then trash it. If it’s already trashed you’ll have to reinstall it in order to disable it!
The Installation Process
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  It’s advisable to format your hard disk drive before installing a new system.
If not, you should use Disk First Aid to verify the drive and Apple HD SC Setup to
update its driver software.
Àú The latest versions of Disk First Aid and Apple HD SC Setup come with the Installer.
Å Don’t use Apple HD SC Setup on a PowerBook 150, Quadra 630, LC 630 — or any
other Mac or PowerMac fitted with an IDE internal drive
√Ö Installation puts the System Folder onto logical sectors of the drive for optimum
performance — ALL disk faults must be corrected before installing a new system
Before proceeding with an installation you should:-
z Turn off RAM Disk in the Memory control panel
z Quit all applications
z Disable all extensions and control panels and restart the machine
The installation process can take from fifteen minutes to an hour.
√Ö You can install a system on any drive EXCEPT the startup disk
√Ö For efficient installation always start up from the Installer Disk
Installation from Diskettes
  This is the only option if you have a Mac without any system installed and you
don’t have a removable disk drive!
System installation software often comes as a set of diskettes — additional sets may be provided for optional system extras. On the first disk of each set there’s the Installer application which does the installation work for you.
As a precaution you should make copies of all the disks before starting the installation — but if your Mac is out of operation you won’t be able to! You can use a diskette copying utility, such as DiskCopy, to create image copies that are exact replicas of the originals.
To install the system:-
z Lock all the installation disks
z Shut down the computer
z Insert the first floppy in the System Installation set
z Restart the Mac
z Follow the instructions provided
Repeat the process for any extra sets of installation disks.
Installation from a Removable Drive
  This is much quicker than diskettes — and prevents the originals from getting
damaged. If you’ve a CD-ROM or other removable drive containing installation
software you should proceed as follows:-
z Lock the removable disk (as appropriate)
z Insert the removable disk ◊
z In the Startup Disk control panel select the removable disk ◊
z Shut down the computer
z Power up the removable drive
z Insert the removable disk
z Restart the Mac
z Double-click on the appropriate Installer
z Follow the instructions provided
◊ Omit these steps if no System Folder is present on the Mac’s startup drive
If there are any extra installation sets on the disk you can start these installations by double-clicking on the appropriate Installer icon.
When you’ve finished you should make sure that the Startup Disk control panel is restored to normal. This ensures you don’t start up from the removable disk again — it won’t anyway if you’ve ejected the disk!
You can prepare a removable disk for installation using the installer diskettes.
Proceed as follows:-
z Insert the Disk Tools diskette and drag its icon onto the removable drive
z Drag the System Folder from the new Disk Tools folder and place it at the
top level on the removable drive
z Eject the Disk Tools diskette
z Create a new folder called System Installation on the removable drive
z Insert each installer diskette in turn, dragging each icon into the new
System Installation folder
Repeat the last two steps with an appropriately named folder for each additional installation set.
Easy Install
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  The Installer defaults to Easy Install, providing a system that accommodates all
the features on your model of Mac. It’s recommended for a simple life — and
particularly for your first installation!
The Installer creates the system files using a kit of parts — if you don’t use Easy Install you could have problems later. For example, files that appear to be identical, particularly the System file, can contain different resources depending on the installation process!
˜ During Easy Install existing items in the System Folder are checked to see if they’re
present and are replaced if they’re missing. Corrupt files or files not created by the
Installer are left untouched. If you have doubts about certain system files already
on your machine you should trash them before installation! See Clean Install below.
Custom Install
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  Custom Install can save a lot of hard disk space since you only install those files
that you really need. Only use it if you really understand what every file is does.
If you need every system file (including those that won’t work on your model) you can choose Custom Install and select every box in sight! This creates a Universal System that runs on any model — useful if you want to start different models from a single external hard disk or removable drive.
˜ Installation takes a long time — so make sure you make the right choice.
˜ You may not be able to select individual items of a certain type — if this happens you’ll
have to go through a complete Easy Install instead!
Clean Install
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  A Clean Install ensures that corrupt files don’t remain in your System Folder.
To implement a Clean Install you must open the main Installer window, press Shift-†-K and select then New System Folder. This installation then creates a completely new System Folder and the renames the old System Folder as Previous System Folder.
You must immediately retrieve any extra system files from the Previous System Folder. These include control panels or extensions that aren’t provided by the Installer — including those supplied by other Apple or non-Apple products.
√Ö You must trash the Previous System Folder immediately afterwards!
System Update
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  A System update is an incremental revision of system files — for example, from
System 7.5.3 to System 7.5.5. It adds new components to the System Folder and
provides updated Apple software.
√π See System Installation above for more about using Installers
The update Installer is similar to a system Installer, but only updates an existing system. For example, System 7.5.5 Update Installer updates files for System 7.5.3 to System 7.5.5. It won’t work for other system versions or if there isn’t any system at all! Note that the System 7.5.5 update only works on any system that’s already updated to System 7.5.3.
As with any installation you should first check the Mac‚Äôs drive using the latest version of Disk First Aid. This is supplied in the Utilities Δí folder in the first diskette (or folder) of the installation set.
Before running the Installer you should ensure that System x.x only is selected in Extensions Manager control panel — you can also select any other essential extensions or control panels for your machine. Then restart the Mac before starting the update.
As with other Installers, Easy Install automatically installs the files for your particular model — you can use Custom Install to add others later. Extra installations for additional system files may have to be used afterwards.
When installation is complete you should check that it’s effective by selecting About This Macintosh…. In the case of System 7.5.5 it should look something like this:-
 
In System 7.5.5 the following standalone files used in previous system versions are replaced or built into the files shown on the right. The Installer should delete these files — but if you’ve renamed them in the meantime you must remove them manually!
Original File System 7.5.5 File
Apple Multimedia Tuner QuickTime extension
Finder Update Finder file
LaserWriter 8.0 LaserWriter 8 driver
Sound & Displays Monitors & Sound control panel
PowerPC Finder Update Finder file
All of the following files are superseded by the new System file:-
  You can use the update Installer to create a Universal System (see above) that
works on any machine, but most Mac users won’t need to do this!
To create a Universal System to version 7.5.5 you must update a Universal System 7.5 to System 7.5.3 with the System 7.5 Updater and then apply the System 7.5.5 Update. You should proceed as follows:-
z Use the System 7.5 Installer and select Custom Install
z Click on the first item’s triangle
z Click on System for any Macintosh and proceed with installation
z Open the System 7.5 Update Installer and select Custom Install
z Click on Universal System Folder and proceed with update
z Open the System 7.5.5 Update Installer and proceed with update
Extra installations for additional system software may have to be left until last.
Reinstating System Files
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  In theory you should use the Installer to replace damaged System files. In practice,
if your original installation was made using Easy Install (or Custom Install with all
items selected), you can replace items by dragging new files into the System Folder
on your startup drive — followed by a restart. The System and Finder files are the
most likely candidates for replacement!
To allow for this you should backup your System Folder or install a full system onto a removable disk. Ideally you should keep the System Installation and System Update folders (containing all relevant Installers and folders) on the same disk as an installed System Folder — this caters for any eventuality! Whilst you’re at it you can include your disk formatting application and a disk-mounting utility such SCSIProbe or HDT Prober.
When you drag individual files into your System Folder there’s a serious risk of disk fragmentation — your system won’t be optimised and could run slower. You can minimise this by only replacing those files known to give problems. Better still, you could erase your disk and then copy just the System Folder onto the drive — you can copy other files onto it later. The result will be reasonably optimised. Alternatively you could use an optimisation program such as the CP Optimizer provided in MacTools.
