SwitchBoot is intended for Mac users who change their boot drive often and wish to shortcut the time involved in waiting through the boot process of the current default drive, setting the new drive in the control panel Startup CDEV, and then rebooting.
Installation:
Although it can be located anywhere in your system folder, SwitchBoot should be the first INIT alphabetically since you want to be able to interrupt the boot process as soon as possible. The INIT is named “ !!SwitchBoot!!” to accomplish this. However, depending on the names of other INITS in your folder, you may need to adjust the name for proper alphabetic placement. If you have any drives which have their own INITS (most often those drives with removable media), your drive’s INIT must alphabetically precede SwitchBoot if you want your drive to be recognized by SwitchBoot if it has no disk in it when your machine starts up. SwitchBoot must be placed in the system folder of any hard disk that you intend to switch from or to, so the best bet is to just put it in every system folder. This will insure that the “one Time” feature described below will function properly. If you do not invoke SwitchBoot by pressing the “s” or “caps lock” key, having it in your system folder will add less than a second to your boot time.
Operation:
After holding down the “s” or “caps lock” key during startup, you are presented with a dialog box containing a list of the currently available volumes with the current default volume highlighted. If no volume is highlighted, then the current default volume is not recognized by SwitchBoot (explained below).
Reboot:
This button is only available if you have chosen a volume which is bootable. Non-bootable volumes are noted. If you choose a bootable volume from this list and press “Reboot”, your Mac will reboot with the chosen volume as the default volume. This volume will remain the default as if you had set it from the Startup CDEV.
Reboot:
This button is only available if you have chosen a volume which is bootable. Non-bootable volumes are noted. If you choose a bootable volume from this list and press “Reboot”, your Mac will reboot with the chosen volume as the default volume. This volume will remain the default as if you had set it from the Startup CDEV.
One Time:
This button is the same as Reboot except that the new drive does not remain the default drive - it simply allows you to accomplish a one time switch to another drive. After rebooting from the new drive, the default drive is reset to the original drive. To do this, Switchboot writes the original drive specification to a temporary file (“SwitchBoot.Temp”) on the new drive. When the new drive boots up, before checking to see if you wish to invoke the SwitchBoot dialog, it automatically checks the new drive for the presence of the temp file and if it finds it, reads the drive specification, resets the default drive, and finally erases the file. Remember, you must have Switchboot on all of your disks for this to function properly.
Continue:
This button allows you to continue booting from the original drive. It is only available if the Mount or UnMount buttons have not been used. This helps avoid potential damage to removable disks that have been switched while the system is still in an unsteady state. Rebooting from these disks should pose no problems, but continuing to boot from another drive after a removable was switched was considered too risky.
UnMount:
This button is only available if the selected drive supports removable media and there is a mounted disk in the drive. This button unmounts a volume in the drive so that it may be replaced with another volume. The list is updated to indicate the unmounted volume.
Mount:
This button is only available if the selected drive supports removable media and there is no currently mounted disk in the drive. This button mounts a volume placed in the drive. The list is updated to indicate the newly mounted volume.
ReScan:
This button rechecks the drive queue and updates the list. Use this button if you think that the list does not contain the correct information.
Shutdown:
This button simply powers down your machine in an orderly fashion.
Caveats:
• SwitchBoot was originally intended for internal use. Reasonable attempts have been made to insure its reliability and, although it has not caused any known problems in many hours of use, it has not been subjected to exhaustive testing. Although the nature and design of the INIT should minimize the possibility of problems, any program which directly accesses your drives, particularly in the midst of the booting process, should be viewed with a jaundiced eye. As a result, be advised that you use it at your own risk.
• SwitchBoot filters out any devices which are not classified as hard disks or any devices which are not directly connected to your machine. This means, for example, that it ignores CD-ROM drives and hard drives which are accessed through a network. It should be able to recognize non-SCSI hard drives connected to your machine (e.g. the HD-20), but it has not been tested for this compatibility.
• SwitchBoot also does not recognize hard disks connected to the Nubus or PDS slots. The only exception to this is if your machine just booted from a Nubus device and it is the designated default startup drive. In this case, the drive is indicated by its Slot and Device ID and may be selected to reboot from. (I was not able to test this feature. If it works, please let me know.) When more of these cards become available and if anyone requests it, I’ll look at adding the capability of identifying and rebooting from additional Nubus drives.
• SwitchBoot only works on an SE or newer machine. It does not work on the earlier machines since Parameter Ram was not designed to hold boot device information beyond a preference for floppy drive 1 or 2.
Legal:
SwitchBoot may be distributed freely, provided that no charge other than the cost of media or normal downloading costs is imposed. There are no shareware fees except a request to be a little more environmentally sensitive whenever you have the opportunity. Credits and copyright notices must be retained. No Warranties are expressed or implied.
Change History:
• 1.1
- Added “One Time” ,“Continue” buttons and Caps Lock invocation. (Feature and Implementation ideas by: Alex Chaffee, Reed College)
Feedback:
All problems, questions, comments, criticisms, suggestions, etc. should be directed to:
