With the release of the Quadra 840AV (it also comes with the 660AV), among the many goodies that Apple included with it such as speech recognition and speaking capabilities, Apple also included with it a new control panel called Auto Power On/Off. Auto Power On/Off does exactly what its title implies and permits the user of a System 7.1 machine that is capable of soft-power on (i.e. power on by the keyboard power key) to schedule the Mac's shutdown and startup times. However, so far as I can tell, it only works on the following three modular Macs: Quadra 840AV, the IIvx, and the IIsi.
The control panel consists of a number of options, one section controls startup times, one controls shutdown times, and a few extra options control warning times given for the shutdown of the Mac, as well as an "auto-restart in event of power-failure" feature. Auto Power On/Off provides two options for startups or shutdowns. One option is a scheduled "one-time only" startup/shutdown, and can be specified to occur just once. The other option is recurring, i.e. the machine can be set to turn itself on or off on any of the days of the week, weekdays, or weekends. As for the additional warning time options, Auto Power On/Off provides an option of whether or not a warning is needed before shutdown and how long ahead of the shutdown time to give the warning. If the warning is set for more than an hour ahead of time, the machine warns the user at one hour, fifteen minute, ten minute and one minute before shutdown. Settings are saved in a Preferences file in the Preferences folder.
The auto-restart in case of power failure feature is a mixed blessing, depending on your electrical situation. The idea behind it is that if the power is suddenly cut off at the source, as in an electrical blackout (but not if you hit the power switch at the back of the machine), the Mac turns itself on when the power returns. All in all, for a small 47K control panel, it packs a variety of useful power supply options, allowing scheduling of startup and/or shutdown times, at a user-determined interval, to warning options, and the ability for an auto-restart in event of a black-out.
The Shutdown process is just as if the user had actually chosen Shutdown from the Finder menu, and thus can be stalled if the user has open applications with unsaved changes at the time of shutdown. If the user wants a machine guaranteed to shut down regardless of the status of various changes, various third party programs help with that, such as ShutDown Items.
Why Apple has not implemented this feature in other machines is impossible to say, especially since this feature is not new, and was in fact documented in the IIsi developer notes released in 1991. However, all is not lost to those who don't have the IIsi/IIvx/Quadra 840AV, since there are several third-party hardware devices that work on all ADB-capable Macs. These devices include the PowerSwitch LT from Radiant Enterprises, the PowerKey from Sophisticated Circuits, and the SmartBar from Sequence Electronics. [I have more information on the PowerSwitch LT and the SmartBar planned for a future issue. -Adam]