I didn't realize at the time how fortunate I was to have a Tandy 1000HX when I was growing up. It was one of the only PCs I'm aware of which had DOS in ROM. Of course you were stuck with DOS 2.2 or something. But startup times were beyond almost every device I've used since, and certainly miles ahead of any PC.
Here's a quick demo from a similar Tandy model: https://www.youtube.com/watch?v=DaSkda4XW3k