I can't rully run Minecraft on a Pentium-era PC yet... · 11:47pm Nov 4th, 2017
But I can run it on a 300MHz Pentium 2!
Specifically, I ran Indev at a laggy 12-15 fps, and 1.5.2 at ~5-6 fps.
I suspect that the CPU is the bottleneck, 'cause Minecraft is much more CPU intensive than it is on the GPU.
Though, I do have a 400-something MHz Pentium 2 in storage that I pulled from a different computer...
Either way, the thing can barely play Youtube videos at 144p, and it actually surprisingly loads Fimfiction pretty quick.