This is not something I would expect anyone else to ever notice, but... has anyone else ever noticed that a lot of TV shows from the '70s and '80s don't have any fades or any other transitions to commercial breaks? Especially action shows. If you watch The A-Team (or virtually any other Cannell production) or The Fall Guy and a whole bunch of other action shows that are even more obscure and have even more car chases and explosions, they never fade out or fade in; when it's time for a commercial, they just cut to black, and when the commercial break is over, they cut back to the next scene. It's clear that the negatives don't have any fade-outs or fade-ins and instead they just insert breaks where the commercials are supposed to occur, but there's nothing else to get us in and out of commercial breaks.
I never really noticed this before and I probably shouldn't have noticed it now, but I find it odd, since I'm so used to network television shows making a big deal out of act breaks. Even when they don't fade out, they find some way to tell us that the act is over. Like the "whoosh" music sting that Buffy the Vampire Slayer had before every act break and which other shows have copied since then. These shows have nothing like that. A lot of times the act breaks don't even occur on anything exciting; they'll go out and go back in again almost at random.
I think the first show to do away with fade-outs and fade-ins might have been Mission: Impossible, which also did away with dissolves and most other optical effects. The point there was to keep the tension going at all times; the time it took to fade out or in would dissipate the tension just a little bit because when you fade, you have to "hold" on the action just a little bit. That's probably one reason for these sudden transitions. Another reason may be that a lot of these action-adventure TV writers were influenced by Roy Huggins, who believed in writing without act breaks because "a good story can break anywhere." That would explain the seemingly random breaks.
And it might just be that the idea was to make it easier to sell these episodes to overseas markets; overseas networks might want to put commercial breaks in different places (or have fewer commercial breaks) so the negatives of TV episodes were prepared without breaks.
In fact it's kind of a shame, if a minor one, that the DVDs of these '80s shows don't take the obvious step and join the acts together without the one or two seconds of black screen -- take those out and you'd have episodes with no visible commercial break points at all, which would make the DVD experience more fun. I feel the same way about the DVDs of the U.S. version of The Office (another show with no fade-outs or fade-ins) -- it would be so easy to take out the commercial break spots and I think it's basically laziness on Universal's part that they don't do it.
This has been the most nit-picky post ever, but hey, at least it's not negative.