Another thing to bear in mind, since many people are talking about how convenient iPads are for older parents (I too gave my parents an iPad Air a year or two ago - they get a lot more use out of it now than the MacBook I gave them about 8 years ago...): their definition of "unbearably slow" and our definition are really markedly different!
I'm not sure I'm the age of your parents, but even as an over-50 tech nerd, I am quite happy with my iPad 1. I use it as a reader, an alarm clock, and a terminal emulator on a daily basis. The battery still keeps its charge and it is one of the most solid pieces of tech that I have ever purchased.
Students always come into my office and wonder why I don't have "a good computer" or why "everything is so old" (which admittedly the Apple //e is), but if the only software you need to run is a terminal and a browser, then upgrading your hardware becomes a lot less critical.
I just recently pulled out my old iPad 1 and charged it. I was marveling at how well-designed it is, and how much I miss the simpler OS that runs on it. It's since been supplanted by my iPhone, MacBook and Surface, but I'd love to have a good reason to use it again :)
I use the original Prompt from Panic and the Apple bluetooth keyboard. I also have the charging stand which keeps the iPad in portrait mode. I would have preferred landscape for emacs, etc., but it is certainly usable.
