Getty Images In 1990, Bill Gates showed off Windows in one of its traditional forms: a shrinkwrapped box.

Way back in 1975, Bill Gates and Paul Allen founded Microsoft to sell a version of the BASIC programming language for MITS’s Altair microcomputer. Their idea–producing essential system software for computers manufactured by others–turned out to be one of the greatest business models in the history of business.

And now, thirty-seven years later, the company may be about to try something new. It’s scheduled a press event for next Monday in Los Angeles, and Sharon Waxman and Alexander Kaufman of The Wrap are reporting that it will announce a Microsoft-branded tablet which will presumably run Windows RT, the version of Windows 8 for iPad-style tablets using ARM chips.

Microsoft isn’t new to the hardware game, of course: It’s created everything from mice to the ill-fated Zune to a robotic version of Barney. But if it’s ever sold a true computing device under its own name before, I’ve forgotten about it.

[UPDATE: On Twitter, James Kendrick reminded me of the Xbox, which, even if it didn’t start out as a “computer,” is looking more like one all the time.]

It’s pointless to speculate much until we know more about the device in question–assuming it exists–but it’s not hard to see why Microsoft might want to do this, even though the company runs the risk of ticking off other hardware manufacturers who it wants to use its software. The iPad is doing so well mostly because it’s so good; it’s so good mostly because Apple controls every aspect of the experience, from the hardware to the software to the services. By putting its own operating system on its own tablet, Microsoft can create a far purer iPad rival than if it relies on other companies to design the device.

(If third-party manufacturers treat Windows 8 as poorly as they usually treat Windows–larding it up with useless utilities, pushy security software and unwanted demoware–it’s going to be ugly, and the iPad will continue to stand alone.)

Surprisingly, given how much of a head start Android tablets have on Windows 8 ones, Microsoft still has a shot at building the first truly polished, popular iPad alternative. I never thought things would pan out this way, but it seems possible at this point that Android tablets will never quite take off.

Of course, the last time that Microsoft attempted to take on Apple with a hardware product of its own, it was the Zune, which never went much of anywhere. Nor did it really deserve to succeed: While Zunes weren’t without their virtues, every new model seemed to be chasing after last year’s iPod.

Until now, iPad rivals have suffered from a similar fate. Just when manufacturers figure out how to make something roughly comparable to an iPad, Apple releases a new iPad that raises the bar. But if a Microsoft tablet manages to make for a worthy alternative to the new iPad–either because it’s in the same ballpark or because it goes off in another direction–this could be fun.

Lots more thoughts to come.