The first computer I owned was a Sinclair ZX-81 (the original of the TS-1000). I built it from a kit. I still have it packed away somewhere, although the keyboard died. Loved that lil' thing ... still do, really, in some corner of my mind. I wrote a Galaxians game for it in 2k of memory (shared with video, I might add) ... didn't even have space for a hex loader, had to poke the whole thing in. Yeah, in Z80 machine code. It didn't play a great game of Galaxians, either -- there was no room for elaborations like keeping score -- but it did play. I suppose it says something about me that my next program was a D&D dice roller ... and a dozen or so years later, I was selling a descendant of that program at GenCon.
My first Usenet post was to net.flames, long before the Great Renaming. I think that says something else about me.
(actually, I'm not 100% certain of the name anymore, except it was .flames, and it was in 1981, and it was from a real, honest-to-God PDP-10)