If it wasn't for the fact that I had a summer job between my junior & senior years in high school, I'd probably have been vegging out on the sofa watching The David Letterman Show. The future late night legend's 1st talk show was a mid-morning effort that lasted 4 months (June-October 1980) on NBC.
In fact, I did watch the show briefly when the summer gig ended. There was a little period of transition at the end of August. By that time, Bill Wendell, a long time NBC studio announcer, was working with Letterman, and would join him on Late Night 2 years later. Veteran newsman Edwin Newman, who had the 12:55 (ET) newsbreak, was inserted to do news briefs at least twice per day. The series started off at 90 minutes, then was trimmed to an hour due to poor ratings. Folks just weren't ready for a live, comedy-oriented chat fest that early in the morning. Then again, with Today having mutated to 4 hours these days, maybe now they are.
Comic Rich Hall, a frequent guest, was also one of the writers. Bob Sarlatte was the original announcer, but was sacked after just a few weeks, so it's Wendell you'll hear in the following clip. Oh, by the way, that's Casey Kasem (American Top 40, etc.) intoning, "This is NBC" before the show starts.
The early cast of Saturday Night Live were known as the "Not Ready For Prime Time Players". It's unfair to say Dave wasn't ready for daytime (he'd been a panelist on The Gong Show at least one week), but that his brand of comedy didn't fit. 35 years later, as he's getting ready to retire and turn his CBS show over to Stephen Colbert, he can look back on this and laugh with the rest of us.