For me, the biggest moment in my computing life, or certainly one of the biggest moments, was years ago, ( more than 20 years cos it was in my old flat ) on my humble Atari MegaST.
I bought a 40MB HD from a guy ( Way back when ads were placed in monthly Mags and it took easily 2 months to get something sold off due to there not being a WWW like there is today )
Anyway, at the time I had a Quantum 540 and this guy was selling this 40GB and so I jumped at it and when it came, I set about seeing what the guy had deleted and I was almost completely and fully able to recover a whole load of files off it... That was back when I knew what I was doing and recovering files from a SCSI drive was easy, but laborious.
Anyway, on the Atari, the user interface OS was called GEM ( Graphic Environment Manager ) and it was basic as best, but it did have very basic Multitasking capabilities in their ACCessory Apps, btu there was a couple of after market programs out there that allowed full multitasking and one of them was MAG!X later renamed MAGIC and this had Mag!X V2.1 on it, also in order to use the Multitasking OS, it had to have a Multitasking capable UI and again, there are a few, and this had EASE. Anyone who knows about Linux, will know that this is just like the various versions of Linux and the various versions of the Desktop, and you can look at EASE, THING, TERADESK, Jinnee etc kind of like Gnome , KDE, Mate, XFDE and so on...
Anyway after several days of hard work and perseverance, I had managed to get my humble rubbish Atari ST from a basic computer, to a fully multitasking machine.
Even to this day, I now use Magic v6.2 and the Jinnee Desktop on my TT030 and MiNT and Jinnee on my Falcon060.
Mint is very much a unix extention for the Atari computers and it allows Ataris to also run X Apps and also gives them Unix Filesystems.
Waffle. mode = off
This must be one of the biggest moments in my computer life.
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Second biggest jump, was when I bought my first 3D Card... The Orchid Righteous 3D and it allowed me to play UT Classic with my Cyrix 333 against my mate who had a Maxi Gamer 3D on his P200MMX
Oh those were the days!