What is the oldest PC you have ever used / owned? For me it was a Zenith Data Systems PC from 1987. It runs Windows 1.0 on top of DOS and takes a few minutes to calculate 1 + 1. If I tried to divide by 0 I'd probably get a GSoD because it has a green screen.
Not sure on the specs, but I bet it has less than 256 KB of RAM.
My first computer was a Timex Sinclair ZX/81 that my dad built from a kit in 1982. It came with a whole 1K of RAM, but my dad added the 16K expansion pack. It used a standard cassette player to save and load data. Also, my dad hated the tiny membrane keyboard that was part of the kit, so he went to the local electronics store and found a full-sized keyboard from an old IBM mainframe dumb terminal and wired that up to the ZX/81 instead.
Quote