I used a Commodore 64 from 1981 through 1988 or so. A whopping 39k of usable memory. Never did a single upgrade to it...OS, RAM, disc...nothing.
And yet, the software and games for the system continually improved from year to year even though the platform, itself, did not improve.
This is the result of writting better, more optimized code as time went on. They were forced to squeeze everything they could out of what they had to work with and did it.
Now? Buy more RAM. Get a quad CPU. Get a $350 video card. Nobody optimizes anything anymore which is why Vista is garbage.
And yet, the software and games for the system continually improved from year to year even though the platform, itself, did not improve.
They still have a users group making Atari 2600 "homebrew" cartridges today using only 4k or 8k(bank switched) cartridges.
Atari Homebrew Cartridge reviews on CNET (VIDEO LINK)
Amazing stuff they squeezed onto such a small space back in the 70's and even moreso now with the tricks they've learned to write even more concise coding.
I can't find it right now, but someone over at Atari Age made a primitive "windows-esq" fun utility environment for the Atari using the standard 4k cart. It had the pointer you used a joystick for in place of the mouse that it was trying to represent. I had desktop icons, and there may have been a game of pong as one of the icon you clicked on.
Another cool utility was a synth cartridge using it's 4 voice registers to create some interesting sounds/music style samples. Sounded contemporary evn with the limited sound registers the Atari was known for. Check it out.