This one runs an hour and I don't expect you to watch it all…but someone posted to YouTube, an entire David Letterman Show from September 12, 1980. This was Dave's morning show, the one he did for NBC that went largely unwatched…and I don't think it's hard to see why. He's the wrong guy for the time slot and he's also a little too smartass. You get the feeling that he doesn't even take his own show seriously so why should you? Plus, he feels all alone out there…no sidekick, no bandleader with whom he has any rapport, etc. Doesn't it feel like half the staff didn't show up for work that day but they made Dave go out and do his show anyway? Add to this the largely non-responsive studio audience and you have a rather cold, impersonal program that probably wouldn't work in any daypart but was certainly all wrong for weekday morns. And just to really finish it off, you had these news breaks that often led to awkward transititions back to comedy and light banter.
A year or two earlier, I'd become a big fan of Mr. Letterman's, seeing him act as emcee (or sometimes just a performer) at The Comedy Store up on Sunset. On that stage, he came off as polished and professional, especially compared to some of the other comics…and of course, it was amusing to see him act like we were all foolish to be there and it was even more ridiculous for a grown man to be doing what he was doing. That was The Comedy Store and it was late and half the audience was drunk, anyway. On NBC's daytime schedule, the same attitude drove viewers to reruns of The Jeffersons or whatever was over on CBS.
(I just checked and I was right: Reruns of The Jeffersons. Dave's show started as 90 minutes on June 23, 1980 and was cut to 60 minutes after about six weeks. It ran as an hour show until October 24 of that year, whereupon its time slot was handed over to two game shows, Las Vegas Gambit and Blockbuster. After that, NBC kept Letterman on the payroll until February 1, 1982 when he took over Tom Snyder's spot after Mr. Carson.)
So this is an interesting bit of history and like I said, I don't expect you to watch the whole thing. It's in seven parts and they should play, one after the other, in the player I've embedded below. You might watch a little of the opening and then leap ahead to the start of Part Four where Dave does a remote segment with some New York street vendors. Take a gander.