Yeah, I had a pretty new PC (my first one after heavy-heartedly switching from the beloved Amiga to the despised PC) when Doom was released, and all my friends

Yeah, I had a pretty new PC (my first one after heavy-heartedly switching from the beloved Amiga to the despised PC) when Doom was released, and all my friends would come over to play because it could run it full screen (older 386 and weaker 486 CPUs were not fast enough, so you had to reduce the size of the game screen and play with an ugly static border around it). Then just a few years later I installed the Quake demo and all I got to see was an error message. The PC had a pretty exotic IBM "Blue Lightning" CPU which was a "486SX3", i.e. it ran at 75 MHz internally, 25 MHz externally, and didn't have a built-in FPU - which was a requirement for Quake. So I realized it was time to upgrade to a Pentium CPU...