Frequently Asked Questions
About System 7.5.5 Update

The following is a list of the most commonly-asked
questions about System 7.5.5 Update. More information will
be added as appropriate.

1) What is System 7.5.5 Update?

This is a three-disk set of system software enhancements
that delivers improvements in stability and performance
improvements for Macintosh and Mac OS-compatible computers.
This important update is for all Macintosh and Mac
OS-compatable computers running System 7.5.3, and will
update a system to System 7.5.5.

2) Who should install System 7.5.5 Update?  

Apple is recommending that any Macintosh or Mac
OS-compatable computer with System 7.5.3 install this
update.

3) Should I install System 7.5.5 Update if I do not have
System 7.5.3?  

You must have System 7.5.3 in order to install this
software.  You can tell if you are currently using System
7.5.3 on your system by choosing "About This Macintosh"
from the Apple menu. In the top right-hand side of this
window will be the system software information.  Your
system has System 7.5.3 installed if it reads:
	System Software 7.5.3

If you have System 7.5, 7.5.1, or 7.5.2, you can update to
System 7.5.3 by obtaining System 7.5 Update 2.0.  If you
have a version earlier than System 7.5, you will need to
purchase it from an Apple reseller, or by calling the Apple
Order Center.  In the U.S. call 800-293-6617.

4) Do I need to install System 7.5.3 Revision 2 before
installing System 7.5.5 Update?

No. System 7.5.5 Update includes all of the improvements
delivered with System 7.5.3 Revision 2, making installation
of System 7.5.3 Revision 2 unnecessary.

5) What improvements does System 7.5.5 Update deliver?  

System 7.5.5 Update provides reliability improvements for
all systems by eliminating some causes of system freezes
and improves the reliability of sharing a printer over the
network.  In addition, there are a number of improvements
which only affect certain models, including:

More reliable use of the floppy drive on DOS-compatible
systems improved floppy formatting and better reliability
during system startup for high performance (180MHz or
higher) 604 or 604e microprocessor-based systems

Improvements in the reliability of the remote control
included with the Apple TV tuner and Macintosh TV

The elimination of one cause of Type 11 errors on
PowerPC-based systems

More trouble-free networking with the 5400 and 6400 series
systems

Improvements in data integrity when accessing a 5400
series system over the network

More reliable use of sound-intensive applications for
Macintosh Quadra and Centris systems which have been
updated with the Apple Power Macintosh Upgrade Card.
A revised Energy Saver control panel which removes
references to the EnergyStar program.

The performance improvements provided in System 7.5.5
Update are primarily for people who use Virtual Memory
(VM).  The VM offered in System 7.5.5 Update will deliver
significantly better performance when performing specific
tasks than the VM provided in earlier versions of the
system software. Areas where you may see performance
improvements include launching large applications,
switching between large applications, switching between
large documents in applications, and accessing SCSI
devices.  This improvement will vary greatly, however,
depending on the amount of RAM installed in the system, the
amount of virtual memory allocated, and the applications
being used. A revised Code Fragment Manager enables some
large PowerPC-native applications to launch faster, while
enabling some applications to be launched in low-memory
situations. The Universal System Folder capability has been
enhanced to support the latest Apple computers, including
the Apple Macintosh 5400 and 6400 series. With this
enhancement, customers with System 7.5.3 can now create a
single system folder on an external hard disk or
removable-media drive and use it to start up everything
from Macintosh Plus to a Power Macintosh 9500, including
all Mac OS-compatibles.

6)  Why can't I see performance improvements when I run
MacBench with the new Virtual Memory?

The performance measurements made in MacBench do not
measure the particular type of performance improvements
delivered with System 7.5.5 Update. Other benchmarking
programs also may not measure these particular performance
improvements.

7) I sometimes have problems playing Audio CDs with Energy
Saver installed. Does the updated Energy Saver control
panel fix this?

On some occasions when playing an Audio CD on a Macintosh
with Energy Saver installed, the CD will play for a while
and then stop, resetting to track 1 and time 0:00.  This
problem is caused by the Energy Saver control panel and
will be fixed in a future system update. This can affect
all PCI-based Power Macintosh computers. The problem can be
avoided by opening the Energy Saver control panel,
deselecting "Shutdown instead of Sleeping", and then
closing the Energy Saver control panel.

8) The "About System 7.5.5 Update" document says that I may
have to increase the preferred memory size of some
applications by 23K. Why?

System 7.5.5 Update includes a new library of mathematical
routines. Certain applications which use this  library may
require 23K additional memory in order to run. You do not
need to change the preferred memory size of every
application you use. Only change the preferred memory size
for applications which report an insufficient memory
message when you try to launch them. 

9)  What is different about this new math library?

This library includes more efficient routines for
calculating certain mathematical functions. You may see a
slight performance increase when using applications that
use these improved mathematical routines.

10) What tips are there to ensure that I have a more
trouble-free installation of System 7.5.5 Update?

It is very important to read the "About System 7.5.5
Update" document which comes with the update, and follow
the directions on installing System 7.5.5 Update.  

In general, it is best to not to rename or move files
around within your System Folder.  The System 7.5.5 Update
Installer makes some assumptions that certain files will be
in certain places, and if these files are moved or renamed,
files that System 7.5.5 Update installs could be placed in
the wrong place, or not installed at all.

11) Can I install the U.S. version of System 7.5.5 Update
on a system which has a non-U.S. version of the system
software?  

No.

12) When will System 7.5.5 Update be available in other
languages beside U.S. English?  

Apple expects localized versions of System 7.5.5 Update to
be available in many countries within 90 days after the
U.S. introduction.  Please contact your local Apple support
center for local availability.

13)  Why is there no "custom install" and "custom remove"
option for the installer?

System 7.5.5 Update only updates the existing installed
components on your computer. It does not add functionality.
These updates are necessary to ensure your computer is
operating optimally based on your installed configuration.
A custom install option is only available when an
installation provides new features that you may not wish to
install, such as those found in System 7.5.3. Because
System 7.5.5 Update adds no new features to your computer,
the custom install and custom remove options are not
provided.

14) The installer says "optimizing system for speed" during
the installation. What does this mean?

Some resources installed in your System file by System
7.5.5 Update are compressed. The installer expands these
resources to increase system performance.

15)  Along with the announcement of System 7.5.5 Update, it
has been stated that this is the last system software
release for the Macintosh Plus, SE, Classic, Portable,
PowerBook 100, SE FDHD, SE/30, LC, II, IIx, and IIcx
systems. Why are future versions of the Macintosh system
software not supporting these systems?

Future Mac OS releases will require a 68030, 63040, or
PowerPC-based system which support 32-bit memory
addressing, which includes all other Macintosh models. 
However, while future system software releases will not
install on these older systems, Apple will still support
customers with these systems by providing telephone
assistance.

16)  If I have installed MODE32 on a Macintosh II, IIx,
IIcx, or SE/30, does this mean my system will be supported
by future releases of the Macintosh system software?

No.  System 7.5.5 Update is the last release which will
support these hardware systems, regardless if MODE32 is
installed.

17)  Are there any known problems with installing this
update which I should be aware of?

Customers are encouraged to read the document which
accompanies the update, titled "About System 7.5.5 Update".
It has a "known problems section" which documents issues
which Apple wants to make sure are brought to our
customers' attention.

18)  What happened to System 7.5.4?

System 7.5.4 Update, which delivers System 7.5.4, was
released by Apple Computer to a limited distribution, prior
to an anticipated general release.  Shortly after this
limited distribution, a bug in the software was found which
required a revision.  This revision was named System 7.5.5
and replaces System 7.5.4.  System 7.5.5 Update will
install on computers which have System 7.5.4 installed. 

Since System 7.5.4 was released to a limited audience,
there needs to be a way to easily identify this release in
the event one of our customers installed it and is having
specific problems. In order to make identification of 7.5.4
easy, the version number was incremented to System 7.5.5.

19) Where can I get System 7.5.5 Update?  

System 7.5.5 Update is available electronically via:
   Apple ftp and World Wide Web sites
       ftp.info.apple.com
       http://www.info.apple.com
   Most on-line services, including America Online,
CompuServe, and AppleLink.
 
In the U.S. customers also may order the update on three
floppies for $13 by calling 1-800-293-6617, ext. 1322.   
Outside the U.S. contact your local Apple support center
for further information.

20)  What are the system requirements for System 7.5.5
Update?

In order to install the update, you must have System 7.5.3.
System 7.5.5 Update cannot be installed on earlier
versions of System 7.5.

21)  Where can I get more information about the Mac OS?
More information can be obtained about the Mac OS on the
Internet at:
http://www.macos.apple.com/macos/siteindex.html

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