49 - the very first home computer I ever used was Tony van der Kuyl's Apple II in his kitchen in Dundee, playing the "Lemonade Stand Game" wih his son Chris, who would of course go on to do rather well for himself out of computer games. I still remember the green screen monitor with its distinctive 15.7kHz whistle and the big rainbow-coloured ribbon cables to the two disk drives sitting under it :-)

The first computer I owned was a ZX81 that my parents bought me when I was about 8, and (around roughly the same time) a ZX Spectrum for Christmas 1983 and a Jupiter Ace which a friend of the family bought and couldn't get his head round - and which didn't have Manic Miner or Atic Atac, so he got a Spectrum instead. The Jupiter Ace gave me my long-standing love of Forth, which I will attempt to use on any kind of microprocessor I can get my hands on (Z80, 6809/63C09, 6502, 68000, and PDP11 so far).

The first PC-like machine I used was maybe a little later, and was an ACT Sirius, with an absolutely gorgeous keyboard and a monitor with a kind mesh-like thing bonded to the screen as an anti-glare thing, and disks that spun up and down at different speeds. I did some stuff for school in WordStar (vim has become my muscle-memory-first-language, but really the WordStar keystrokes are just under the surface) and printed it out on the screechy howly Epson MX80. Then came the ACT Apricot with a flappy door over the drives and a little LCD and softkeys on the keyboard - a genius idea that it would take over 30 years for Apple to reinvent with the TouchBar :-D

I had to check the date on ms-dos (1981) so I'm pretty sure I got my T1-99/4A (first computer) that same year. It's a pretty sweet machine. Still have it, just need a monitor solution to fire it up.

[I think the first time I touched ms-dos was years later because of getting a Thinkpad. My path was VMS -> OS/2 -> Mac OS (because of Java) and then *nixes.]

[1]: https://www.unige.ch/medecine/nouspikel/ti99/titechpages.htm

34, first family computer was Windows 98 though I'd used some sort of Mac at school the year before. I also inherited my dad's old Windows 3.1 laptop right around that time and got some DOS experience from there (so I do remember Abort/Retry/Fail).

39 - my first PC was a 80486, my first computer ever used was a Soviet PDP-11 clone school PC.

65 - First home computer, ZX81. First college course, FORTRAN on hand punched cards. Response to first viewing of a 10MB Winchester disk in the lab...oooh, incredible!

Still working professionally in information analytics/coding (UK National Health Service)

Likewise... by the time I got my hands on MS-DOS, I'd tinkered with a half-dozen or so other systems, from Commodore PET to IBM System/370.

56 - just old enough to have done a lot of work on PDPs and VAXs before PCs took over science labs.

48, got my start on a Timex Sinclair in 1982!