The situation is similar to the video recorder market. VHS tapes will not run on a Betamax machine, or vice versa. The old Philips 1500 and new 2000 ranges are similarly incompatible. With home computers, unfortunately, the problem is far worse because there are not three or four but some 25 different systems, with further subdivisions for semi- and non-compatible model variations. Just about the only company to avoid this morass is Atari, all of whose micros run the same software, but of course, not the same cartrides [sic] as their VCS video games machines… More here. Thanks to Andy.
The writer of the above article, Jack Schofield, which will take some of you back to the ‘good old days’ has sadly succumbed to COVID-19. Jack has been big in the tech world for decades and is a very sad loss.