I recently happened to re-read Twice Shy, by Dick Francis, aka The Computer Tapes One. I found myself really interested in the timing of it—bye-the-bye, from here on in, there will be plot spoilers, none of which are (imao) at all likely to spoil anyone’s enjoyment of the book, on the off-chance that they haven’t already read it but someday will. Ready?
OK, so: There is not, I believe, a clear indication of what year the action is set in.
The maguffin, which isn’t really a maguffin but serves much the purpose, is a computer program written in BASIC. It is originally written by a computer professional just before the opening of the action, and is saved onto cassettes that fit in audio cassette boxes. The idea of running a computer program from cassette seems to be new-ish but not totally innovative when it comes up; the protagonist works at a school that has one computer, used for teaching, which has a cassette drive. On the other hand, it does not occur to anyone in the story to just go to a store and purchase a computer and a cassette drive or borrow one from any family with a kid, which leads me to believe they aren’t really commonly accessible. Those cassettes were fairly common in the US for home computers (I think I had this one) starting in around 1980. I think, then, that the book is set sometime in 1978 or 1979, maybe as early as 1976 but no later than 1980. The book is originally published in 1981. Given Mr. Francis’ses’s output of more or less a novel a year, and the speed of publishing in those days, it could have been written as late as early 1980, but I think it’s more plausible that it the book is written in 1979 and set, essentially, in ‘the present’.
But.
Halfway through the book, the story jumps forward fourteen years. We pick up again with a new protagonist, the younger brother of the one from the first half, who needs (for plot reasons) to find a copy of the program which will run.
Which means the rest of the book is set in 1993. Or possibly 1992 or 1994, which actually would make a real difference in the computers and computer culture available, I believe. Still, call it 1993.
In 1993 our protagonist is managing a multi-million dollar investment (in horse breeding stock) and does not own a computer or use one regularly. None of the horse trainers with which he works own computers. There are no readily available laptops, either. Nobody owns a printer. The programmer who has been clandestinely using the maguffin program has been updating it, but has continued to write the updates in BASIC. There is no difficulty purchasing a new computer of the same brand as the one it was written on in 1979, and which will run the program without glitches. There is no question or concern about operating systems or platforms; the operating system, more or less, is on the cassettes along with the program. In the 1993 section, a recent graduate programming specialist does mention machine language (was that a thing in 1993?) but shows no surprise or amusement at a BASIC program.
There is no email. There are no chat rooms. There is no internet—there are no modems, and the people who exchange computer programs over the telephone lines just play and record the audio (which was actually a thing, in 1979). Oh, and nobody has a mobile telephone or even a pager; telephones are land-line only. Video recording technology isn’t ubiquitous; people don’t assume that everyone has the ability to record from the TV. For that matter, video cameras in the 1993 of the book aren’t common, at least to the point where it doesn’t occur to anyone to obtain one when it would be useful—it seems likely that by 1993 in real life, racehorse trainers would own reasonable quality video cameras, but I don’t actually know.
I don’t blame Dick Francis, of course. He had no way of knowing how much change there would be in computers and computer culture in the fourteen years he was leaping past. And he doesn’t write speculative fiction, and his readers don’t want to read speculative fiction (from him, anyway). The impression, for the readers when the book came out, is really that the first half of the book is set in the present, and the second half of the book is also set in the present, but fourteen years later. Still… from my point of view, having lived through those fourteen years and then the twenty-five or so years afterward, it really stood out that he had written a future that was exactly like his present. I can’t imagine anyone right now writing something set half in 2019 and half in 2033 and just blithely assuming that the technology wouldn’t have changed at all.
Tolerabimus quod tolerare debemus,
-Vardibidian.

This all made far more sense once I realized that this was Dick Francis and stopped misreading it as Philip K. Dick.
Tomorrow I’ve got to go see a guy about buying a 13-year-old computer from him to see if it will run the 16-year-old software since I can’t find a working 16-year-old computer of the right type on ebay any longer and I can no longer fix the 16-year-old computer I already own that worked until the power outage four weeks ago, and I am quite sure that nothing newer than the 13-year-old computer will work for this purpose. That sort of interval is simultaneously large and small, because there are still many tasks for which that age of computer will work just fine and yet the entire tech world has changed drastically. And yesterday I set up a new-to-me 10-year-old computer which arrived here with a newer operating system already on it than the brand new computer that my wife got three weeks ago hand-delivered straight from the manufacturer.