(FORTUNE Magazine) – Sam Donaldson of ABC News, who turned 65 in March, has become the network's most visible face on the Net. On Sept. 27, Disney-owned ABC launched SamDonaldson@ABCNEWS.com, the first live, regularly scheduled TV news show on the Web. It will be Webcast on Mondays, Wednesdays, and Fridays at 12:30 P.M., aimed at office workers on their lunch break.

Donaldson's show is designed to woo viewers to ABCNews.com, which ranks third among news sites, after CNN.com and MSNBC.com. "If you're trying to speak to people drowning in information, big personalities help you stand out," says David Westin, ABC News president. Since ABC has no all-news cable outlet, Westin intends to use the Net for breaking news and programming that can't be squeezed onto the over-the-air network.

As for Donaldson, who interviewed FCC Chairman William Kennard and Real Networks CEO Rob Glaser on his first program, he's approaching the Internet with his usual gusto. He talked to FORTUNE's Marc Gunther just before the premiere.

FORTUNE: Why on earth would you leave the White House to do news on the Web?

CyberSam: Let's face it, this President has some clout--but it's a lame duck situation. So now's the time to go. The question became, What do I do? Well, I've got a new deal with ABC. I'm doing This Week, of course. I'll cover politics. I'm adding a unit to do hourlong broadcasts. And then there's this ABCNews.com program, which, I'm told, is the first real television-news show on the Net. When I say television show, you should know that I will be seen in a square that's two inches by two inches. You will need excellent eyesight to watch. And we're saving a lot of money on makeup.

FORTUNE: Why broadcast a TV newscast on the Internet, where headlines and stories are available all the time?

CyberSam: This is not a newscast in the traditional sense. If you want headlines, watch Peter Jennings or CNN or go to ABCnews.com. We're going to do news for the Internet audience. Business and finance. The hot stocks. Who's going to win the battle between AT&T and AOL? What about Ford trying to squash a critic's Web page? And we are booking guests, ideally, for every show. You'll see Steve Case or Robert Rubin. Larry Ellison of Oracle has agreed to come on. It's going to be a very free-flowing program, ad lib. It won't be the tightly structured, 15 seconds for this item, ten seconds for this item, then to a commercial. Remember--we don't have to keep it to 14:30. It's a 15-minute program, but what's on after us? Nothing. So we can run over.

FORTUNE: Any interactive elements?

CyberSam: We'll be taking questions by e-mail. And they tell me that while all this is going on, we will also invite you to leave--or at least leave me. Say on this day in history the Warren Commission report came out. We might do a poll. Or they can read the report online. I said to our Internet people, Why should I knock myself out if I have just invited the audience to take a little detour? They said, Sam, they're still on the Website.

FORTUNE: It's sound like the early days of television--make it up as you go along.

CyberSam: That's one reason I'm excited. It's like trying out at 2 A.M. on the overnight show. And if the Internet turns out to be the transmission belt of the future, the potential is huge. My sister-in-law in Jerusalem can watch. We're not limited at all.

FORTUNE: Tell me about your own online experiences.

CyberSam: I have AOL and MSN. I use e-mail at home. I update my stock portfolio, and I use it for reference; I know how to log on, search the Web, and come up with reference material. I've bought a couple of Dell computers, and I've bought some software. So I'm not a total stranger, but I'm not one of those people who live and breathe the Internet. I'm going to need help.

FORTUNE: Since you're known for challenging people with tough questions, here's one for you--what's TCP/IP? [It's the protocol for delivering Net data and e-mail.]

CyberSam: Is it a server or a connection ability? An Internet connector? No, I don't know. But I am going to learn.