PRAM-Reader reads and writes the original parameter RAM ("PRAM") data and the extended parameter RAM data of the Macintosh to a file on the disk. You can make a backup of the content of your PRAM with PRAM-Reader and rewrite this backup back to your PRAM in case the content of the PRAM is lost or you would like to restore old settings in control panels.
About the Parameter RAM
The parameter RAM is a small piece of storage where the Macintosh saves information, for example, about the blinking rate of the cursor. In the extended PRAM there are saved more technical informations, for example, the default AppleTalk zone or the highlight colour. If the battery which supplies the parameter RAM with power loses its charge, the contents are lost. If any program crashes, it could also write garbage into the parameter RAM.
How to Clear and Restore the PRAM ("Zap" the PRAM)
If the parameter RAM data is not valid, the macintosh might not start up. In this case, hold down the command key, the option key, the "P"-key and the "R"-key at startup. This deletes your parameter RAM and should solve your problem, but your settings in some control panels are lost and revert to default. Now you can use PRAM-Reader to restore the old settings from your Backup-PRAM-file back to the parameter RAM. After a restart, your settings and those of the system software will be there again! You will only have to reset your system clock to the correct time.
Using PRAM-Reader
When you start PRAM-Reader, a window with two buttons appears.
The first one saves the parameter RAM settings of your Macintosh onto your hard disk. Copy this file and the application itself to another disk. You should always keep this file containing your actual PRAM-content and the application PRAM-Reader in a safe place.
The other button restores your parameter RAM settings from a disk file. Be careful! All the old contents of the PRAM will be lost and replaced by the settings saved in the PRAM-Reader file. Changes are effective after a restart.
All commands can be accessed through the menus; there are command-key shortcuts as well.
Preferences dialog
You can invoke the Preferences dialog by choosing "Preferences" from the Edit menu.
In the Preferences dialog, you can tell PRAM-Reader to
A) quit automatically when it has rewritten the (x)PRAM
B) don't ask if the (x)PRAM should be overwritten
Restoring the (x)PRAM automatic at startup
When you would like your PRAM becomes reset every startup, you may switch on both options in the Preferences dialog and put the PRAM file you want to write to the (x)PRAM or an alias of it into the Startup Items folder in your system folder.
PRAM-Reader now launches every startup, writes the file to the (x)PRAM (it don't ask you if you want to overwrite the (x)PRAM) and quits to the Finder.
You may also want to take a look on the System Extension "ParamRAM boss" by Kiselyov Oleg (oleg@ponder.csci.unt.edu). You can get it via anonymous ftp at
Thanks to Eric from Los Angeles at "EELEEL@aol.com", Bob Eidson and Alan Weissmann who corrected mistakes in this file.
Thanks to Kiselyov Oleg at "oleg@ponder.csci.unt.edu" who helped me with the extended parameter RAM.
Thanks to Dave Good. He pointed out some bugs in PRAM-Reader.
PRAM-Reader is completely free.
Please report to me any errors or bugs (in the documentation and its spelling, also).
Matthias Wuttke
Hilterweg 14
33803 Steinhagen
GERMANY
Internet: wuttke@stein.teuto.de
You can get parts of the source code if you send me a disk and a self-addressed envelope (□□□of course stamped!!).□ I can send it to you via e-mail, also. PRAM-Reader was developed with Metrowerks Pascal from the CodeWarrior 6 CD and ResEdit 2.1.3. It works fine with System 7, but it should work with older systems, too.
History
1.0 PRAM-Reader worked, but saved only the "normal" PRAM.
1.1 It saved also the extended PRAM through undocumented traps ($A051, $A052).
For informations about these traps mail to Kiselyov Oleg (oleg@ponder.csci.unt.edu) or me.
1.1.1 Corrected and extended this file.
1.1.2 Caught some minor bugs.
1.2 Now PRAM-Reader is a fat binary. I completely rewrote it in Metrowerks Pascal (from the
CodeWarrior 6 CD ROM)
Improved this documentation
PRAM-Reader saves more of the xPRAM (Thanks to Dave Good)
The PRAM can be restored automatically every startup
What does PRAM-Reader save and restore from the (x)PRAM:
･ the entire "regular" PRAM:
- node ID for Modem/Printer port
- modem/printer port configuration
- Alarm clock settings
- default application font
- printer connected to printer port or modem port?
- auto-key rate (the rate at which a character key repeats when itﾕs held down)
- auto-key treshold (the length of time a key must be held down before it begins to repeat)
- caret blink time
- double click time
- speaker volume
- menu blink time
- startup drive is internal/external
- mouse scaling on/off
･ parts of the "extended" PRAM:
- Information for _InternalWait
- Information for _InitProcMenu
Apparently it has smth to do with the way windows
and dialogs appear on the screen
- Some default video settings
- RAM disk (size, on/off)
- System Beep
- Highlight Colour
- Memory/cache flags: 32 bit addressing, cache on/off
- Startup Disk Info
- Default AppleTalk zone
- Network access (LocalTalk/EtherTalk)
- AppleTalk active?
- Latitude/Longitude of the place the Mac is at
If you have more information about the (x)PRAM, please mail it to me.
