SCSI Saver acts like a screen saver, only it works on SCSI devices such as hard disks. After your hard disk has been idle for a selectable period of time, SCSI Saver will attempt to park the heads on the drive and spin down the drive. “Parking the heads” means moving the read/write heads of the disk drive to a safer spot on the drive. The next time you use your hard disk again, SCSI Saver will restart the drive (with a slight delay) and you can continue working normally.
Who should use it?
If you leave your hard drive running continuously, or if you would like to do so, you are a candidate to use the program.
How do I make it work?
Put SCSI Saver into your system folder (into the Control Panels folder on System 7). Open the control panel, select the SCSI Saver icon. Select the drives you would like SCSI Saver to control. Select the amount of time the drive must be idle before SCSI Saver attempts to idle the drive. Close the control panel and restart your Mac for the changes to take place.
You may also select the option to park the heads on all the selected drives when you select Shutdown from the Finder menu. Most newer driver park their heads automatically, so use this option mostly for older drives.
How will I know if it works?
For most Mac drives, you can probably already hear the drive making sounds when it is accessing data. When SCSI Saver idles the drive, you should be able to hear the disk access as the heads move out of the way. On some drives, you may also find that the drive spins down. In that case, the drive will also spin up the next time you need to use it.
Can I continue to work if the drive has been idled?
Yes. If you spend a great deal of time in some programs such as word processors, you may find that the drive goes idle. As long as the drive is not being used you can continue to work normally. The next time your program accesses the disk, the drive will be reset and your program will continue after a slight delay.
What will prevent my drive from going idle?
Any disk access will reset the timer that waits for the drive to be idled. Some programs such as screen savers may read from the disk before they blank out the screen, which will reset the timer. If you have an hourly chime program it may also reset the timer on the first chime since the sounds are stored on the disk. Once the sound is read into memory it may stay there and SCSI Saver’s timer will start after the first time the chime has sounded.
Are there any drawbacks to SCSI Saver?
Yes. First, SCSI Saver has not been extensively tested on different drives and different Mac configurations. Please make a complete backup before you decide to use this program.
Second, there is some question about the “goodness” of SCSI Saver, particularly for disk drives that respond by spinning down. Disk drives are mechanical devices and most mechanical devices tend to wear out faster if they are started and stopped constantly. The trick for using this program for those types of drives is to find a happy medium between constantly starting/stopping the drive and leaving the drive running continuously. You should set the SCSI Saver idle time to reflect the same amount of time that would make you comfortable with turning the drive off and on again.
Why does the mouse jump when SCSI Saver idles the drives?
This is a programming glitch that I will try to correct in the future. The problem occurs because SCSI Saver is taking too much time in a time-critical portion of the system when it idles the drives. For most people, the jump of the mouse should not be a problem. People with time-dependent tasks (such as some types of scanning, modems during data transfer and network servers) may not want to run SCSI Saver if there is a chance their drives will be idled during this time.
Why is there a delay when the drive starts up?
There is a ten second delay built in when the drives start up. This is done to ensure that all devices have reset properly after being idle. Note that the reset command used to restart the drive affects all SCSI devices, regardless of whether they have been selected in the SCSI Saver menu. Some SCSI devices may not take kindly to the reset command, in which case if you encounter problems you should not run SCSI Saver.
If the delay is not long enough, the SCSI command will not complete and in most cases your mac will hang. You can increase the delay by opening the depp resource with Resedit. A template is supplied that explains the fields.
How do I remove SCSI Saver?
Drag SCSI Saver out of the System Folder and restart your system.
Is this program free?
This program is shareware. If you try the program for a while and decide you would like to continue to use it, you should pay a fee for its use. Rather than asking for a specific fee, I suggest that you pay me what you feel the program is worth to you. My address is at the bottom of this document.
For those of you with access to commercial bulletin boards (such as Compuserve, GEnie, MacNet) you may want to consider giving me a “gift of time” on these systems, particularly if you would like me to answer your EMail questions about the program.
I am interested in hearing your comments, suggestions and bug reports. I am also interested in any devices that appear to present a problem when SCSI Saver is used.
I will do my best work with your feedback and change the program as my time permits.
You can send the feedback through any of the means mentioned below.
Any last comments?
I can’t say this strongly enough... please be sure you have a good backup for all your SCSI devices before you attempt to run this program. While I have done my best to ensure that SCSI Saver will not do anything bad to you, I make no guarantees. Please do a backup right now...
Change History
The initial version 1.0
Version 1.1 - allows you to park the heads at shutdown on those very same drives you’ve selected to idle. This was a very small code change but at least it eliminates the need to run one init to idle the drives and another init to park the drives at shutdown. I believe you’ll need at least version 6.0x to run this version.
Version 1.2 - updated to work with System 7. The spin-up delay may be changed in the depp resource using Resedit.
Darrell Pfeifer
1426 8th St. N.W.
Calgary, Alta, Canada
T2M 3K3
GEnie - DPfeifer (almost every day)
Americal Online - Darrell (every few days, although E-Mail is great here)
Internet - spycal!denigma!darrell@cpsc.ucalgary.ca
Compuserve - 72637,3241 (about once a month - mail may disappear)
