Clark Martin wrote:
> My suspicion is that a lot of times when people zap the PRAM or
> rebuild the desktop or both it's really the restart that fixes
> things. But since they zapped and/or rebuilt they assign credit to
> those actions. This is, I think, why zapping and rebuilding are
> recommended so often. Yes, they do work in specific cases, just not
> nearly as often as people think.
Your suspicion is unfounded...
The MacOS has always had the ability to launch the appropriate application by
double-clicking (or Opening) a document file. This is possible because the Finder
stores file type and creator codes in the Desktop File (which is optimized to
400k), and uses the desktop file to display icons and launch applications. All
Macintosh files have a "type" and "creator" code stored within them. The Finder
uses these 4-character codes to associate the appropriate icons to files, and
launch the correct application when files are opened. A "type" code represents the
kind (and format) of the data within the file. "TEXT" and "PICT" are two common
file types. Applications can specify proprietary file types in a BNDL resource
that the Finder reads and stores in the Desktop File; an application like
Microsoft Word has almost 20 different type codes associated with its data and
application files. Since files with standard type codes (such as "TEXT") can be
opened by several different applications, every application also has a unique
"creator" code associated with it. When an application creates a file, it assigns
the file the appropriate type code, and also gives it the application's creator
code. When that file is opened, the Finder looks up the creator code in the
Desktop File and opens the document in the application associated with it. With
the introduction of System 8.0-9.x, the Finder can present a dialogue box if it
cannot find the creator application on the hard drive. The dialogue box presents a
list of applications that can open the document's file type. The dialogue box also
lists applications that can open the file if it is automatically translated by xxx
or XTND translators. The "Desktop File" actually refers to two files; one a
database of "type" and "creator" codes, and the other storing the various icons
associated with them. If the "desktop file" is corrupted, files may not be
displayed with the correct icon, or they may be opened in the wrong application.
If the Desktop File contains old or outdated information (perhaps a newer version
of an application has been installed), similar symptoms may appear. The Desktop
File has been linked to unexplained crashes and freezes, it is usually a good idea
to periodically rebuild the Desktop File to keep its contents up to date; but if
you are experiencing problems, rebuilding the desktop doesn't hurt and may solve
the problem. The Desktop Files are invisible files stored in the root level of
every Macintosh volume. Hard drives (or hard drive partitions), CD-ROM drives, and
floppies all contain Desktop files containing information concerning the files
present on the volume.
The Parameter RAM (PRAM) is hard memory on the Macintosh, that IS NOT RESET each
time the computer is
shutdown or restarted. Performing a reset or zapping of the PRAM may affects the
following areas:
Status of AppleTalk
Serial Port Configuration and Port definition
Alarm clock setting
Application font
Serial printer location
Autokey rate
Autokey delay
Speaker volume
Attention (beep) sound
Double-click time
Caret blink time (insertion point rate)
Mouse scaling (mouse speed)
Startup disk
Menu blink count
Monitor Depth
Virtual Memory
Ram Disk
Disk Cache
Since the PRAM destroys many of the "Control Panel" settings, it will be necessary
to check critical ones for
the correct settings. Resetting PRAM and NVRAM on Power Macintosh, iMac, and iBook
Computers:
1.Shut down the computer.
2.Locate the following keys on your keyboard: Command, Option, P, and R. You will
need to hold these keys down simultaneously in step 3.
3.Press the Power button, then hold down the Command-Option-P-R key combination.
You must press this key combination before the gray screen appears.
4.Hold the keys down until the Macintosh restarts itself twice.
5.Release the keys after the Macintosh restarts three times.
The parameter RAM and the non-volatile RAM in your computer is reset to the
default values. The clock setting are not changed. Resetting PRAM on PowerBook
computers resetting, or zapping, the Parameter RAM (PRAM) when the computer is
shut down also resets the power manager. The Power Manager is an integrated
circuit that is usually on the logic board of the PowerBook and iBook. As
the name implies, it is responsible for power management of the PowerBook. It
controls backlighting, hard disk spin down, sleep and wake, some charging aspects,
trackpad control, and I/O as far as looking at the serial port and modem so it
doesn't sleep when connected.
Over time, the settings in the Power Manager may become unusable, which can result
in operational anomalies with the PowerBook. Examples would be not powering on,
not waking from sleep, not charging the battery, or not seeing the AC Adapter,
among others.
Restarting is not the answer. I personally shut my macs off every night when I go
to sleep and turn them back on again when I need them. I do no believe in
"sleeping" a computer. If you turn your Mac off and unplug it, it is safe. If
you sleep it, it may fall victim to electrical spikes and surges, power outages
or earthquakes. I ask you this: "would you leave your car idling in the driveway
all day?" I didn't think so.
btw...my Tibook sleeps in the "off" position on my nightstand. I guess I am just
sick.
-- Kyle H. Hansen
Apple Certified Technician
Apple Hardware Technician
Macintosh Server Administrator
www.frankenmac.com
[EMAIL PROTECTED]
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