While the concept hasn't been highly supported over the standard external unit-indeed, it is still regarded in some quarters as electronics heresy-several technical advances, and Guardian's own shift in focus from home audio/visual equipment to the OEM PC environment, may prove a shot in the arm. Another boost will come from the continued "convergence" of home entertainment equipment with the home computer.

But separating the hype from the practicable ultimately occurs at the applications boundary. And while internal UPSes have reportedly been seen in some Midwest retail outlets, observers and participants agree that an OEM connection will be the single most critical element to the idea's success. For one thing, most home-PC users don't want to open up that machine. Further, UPS cards appear destined to be power-limited.

There will need to be sufficient area inside the PC to mount battery packs, and probably management circuitry therein to handle the increased heat. Safety in handling batteries in harsh environments isn't the problem it once was, but heat will cut into lifetime, and users will ideally need to get at batteries quickly for servicing. The card will also need to provide all an external UPS does. On the marketing side, machines are getting faster but smaller, and the demand for home PCs today isn't what it was.

Thus, the future could go either way. User demand is normally a telltale indicator. But even that's a murky area: Most UPS providers haven't seen any quantifiable increase in demand for tn-the-box modules, but they do report having gotten some queries as a matter of general interest.

Nevertheless, whenever there's lingering discussion on the merits of a technique-and praise, albeit mixed with a splash of vinegar, for the innovators-it usually indicates slow but sure movement toward the goal in question.

That will probably be the case here. The only difference may be the timetable, with arrival sooner rather than later.