Will Sleeper work with my… (fax modem, bbs software, backup utility)?
Sleeper will work with any software. It has no knowledge of what program is requesting data from the disk - it merely spins it down when it hasn't been used for a while, and spins it up when there is a request to read or write data.
For fax modems, remember that it will take the disk a few seconds to spin up before the fax can be received. It's best to set your fax software to answer on the first ring to ensure that it can access the disk before the phone stops ringing.
Will Sleeper work with my current screen saver?
Sleeper will work with screen savers that support the 'SAVC' and 'SAVR' Gestalt selectors, such as After Dark. This means that the hotkey will put the disk to sleep and trigger an alternate screen saver if Sleeper's screen dimmer is turned off. If the "only if screen is dimmed" checkbox is used and Sleeper's dimmer is disabled, Sleeper will check for another screen saver instead of its own.
Note that After Dark 3.0 users should be running the latest revision (3.0b at this writing). Earlier versions, notably After Dark 3.0 (without the "b"), have bugs which can cause crashes.
My hard disk never spins down or keeps waking up - why?
Something is accessing the disk. Some possible culprits are:
The Finder:
When "calculate folder sizes" is turned on in the Views control panel, the Finder will periodically check the sizes of files, reading the information from disk.
Even when "calculate folder sizes" is turned off, the Finder will check some information periodically. To make sure that this checking does not wake the disk, set the disk cache in the Memory control panel to be 192K or higher.
After Dark:
Loading a screen dimmer module from disk will wake a sleeping disk. One way to avoid this when using After Dark's "Randomizer" module is to set it to "1 module" to avoid switching modules after After Dark has been activated.
Norton Utilities FileSaver:
This utility may access the disk during idle time, depending upon the settings you have used with it.
Automatic compression or defragmenting utilities:
If you have one of these set to do its work during idle time, it will spin up the disk to do its work.
File Sharing:
If your Mac is on a network with file sharing enabled, someone at another Mac may use your hard disk. File sharing also periodically checks the disk to check for changes in permissions. You may have to increase the disk cache in the Memory control panel to 256K or more to prevent these checks from actually accessing the disk.
Why do all my drives stay awake when I'm only using one?
Sleeper is designed to keep all disks awake if one is active. If you're working, you probably don't want to have a disk spin down. The Finder, standard file dialogs, and other parts of the Mac system access all the disks fairly frequently when your Mac is in use, so the disks will just keep spinning down and back up again, and you would have to stop and wait for them to do so.
The screen on my Quadra 660AV or 840AV doesn't dim. Why?
There appears to be a bug in the initialization of the on-board video on the AV Macs. If you start up with a non-multisync monitor set to 16 or 24 bit mode (thousands or millions of colors), modifications to the monitor's gamma table don't do anything, so the screen won't dim. To work around this, command-option-click on the "Info" icon in the Sleeper control panel and turn on the AV workaround checkbox. At startup, this will toggle the screen depth to 256 colors and back to your original setting, causing the screen to flicker, but also causing the gamma table to be correctly initialized.
Why are all the disk checkboxes disabled on my Quadra/Performa 630?
The Quadra/Performa 630 series use IDE drives for their internal hard disks. Sleeper only supports SCSI hard disks.
My Mac freezes when the screen dims or undims. Why?
With certain hardware drivers (the Radius Color Pivot Display Card is the only known culprit at this writing), the method which Sleeper uses to dim the screen can cause problems. To work around this, command-option-click on the "Info" icon in the Sleeper control panel and click the "Turn off VBL task for screen dimming" checkbox. You must restart your Macintosh before this change takes effect.
How does Sleeper deal with multiple SCSI buses?
Sleeper currently relies on the SCSI Manager's "compatibility mode" to handle multiple SCSI buses. The SCSI Manager will return the first device that responds at a given SCSI ID, so for predictable operation, you should not have devices on two (or more) SCSI buses with the same SCSI ID.
Does Sleeper watch for serial port and CPU activity?
Sleeper doesn't have to. Unlike After Dark, Sleeper doesn't occupy the CPU when your Mac is "sleeping," so there's no need for the sort of monitoring that After Dark uses.
Is Sleeper "Accelerated for PowerPC"?
No. Sleeper is currently written in 680x0 code because the SCSI Manager with which it interfaces is still running in emulation as well. Using PowerPC code in this situation will actually cause your Mac to run slower. When Apple rewrites the SCSI Manager in PowerPC code, we hope to update Sleeper as well.
Does Sleeper work on portable Macintoshes?
Sleeper is not terribly useful on PowerBooks, since it provides the same functionality as the built-in Power Manager. It works, but is redundant so you probably will not find any value in it. Also, a PowerBook's screen should actually be turned off rather than dimmed, since any pattern in the LCD, white or black, can be "burned-in" according to Apple. Fortunately, burn-in on LCD displays is not permanent, and will fade away over time.
