REDMOND, Wash.: Aiming to take over your television screen as well as your desktop, , Bill Gates scooped up an 11.5 percent chunk of Comcast , the country's sixth largest cable operator. That gives him Comcast's stake in @Home Network , an online service that uses cable modems to provide rapid access to the Internet. TIME Business editor Bill Saporito’s view? “Now Bill's got himself a delivery truck. Cable is such a capital-intensive industry because of the equipment. So for Comcast, which has a lot of debt, money is always welcome. It's not really a big deal yet. Gates has so much cash, something like $6 billion, lying around, he's got to do something with it. But he now has a strategic position at the intersection of computers and television.” The move follows Microsoft’s planned acquisition of WebTV Networks , which enables web surfers to read their email and post about politics on their TVs via a set-top attachment. The TV link promises to make impulse shopping on the Web a breeze, and frees up the home computer for other users. Since only about 40 percent of U.S. households have personal computers, but just about everybody has one or more television sets, adding the TV audience and cable’s bandwidth to the Net has powerful implications, expecially for Net commerce. Granting Microsoft’s interactive future a tentative blessing, Wall Street nudged the stock up 1 1/6 points to close at 125 3/8 and pushed Comcast up by 2 15/16 points to end the day at 21 3/8.