Uninterruptible power supplies

If you have ever been caught by a power blackout or brownout — caused by lightning, storm damage, or simply a blunder by a repairman — and have completely lost work which was keyboarded but not yet stored on disk, you know how frustrating and infuriating that experience can be. There is little comfort, at such a moment, in realizing that your work habits should really include more frequent disk storage commands. Nor does it help to reflect that memory resident routines are available which automatically store keyboarded material to disk at frequent intervals.