Anyway, I managed to break my MAME installation, and to have something to do, I installed lxDoom, a Linux port of Doom. I played through the shareware levels recently, and so I started to look around on the net for good Doom levels for single player.
I did manage to find the Doom level I made in '95. Back then, I was still part of the events committee of Thalia, the student association for computer science in Nijmegen. One of the things we wanted to do was a Doom Deathmatch competition. To give everyone an even footing, we decided that the deathmatch should be done in a new level that nobody knew, and with the three of us, we set to designing one. I did most of the work on the 386 that my father gave me, with DEU.
I opened the level, and I was actually mildly surprised at how good it all looked -- in my memories, the level was pretty crude and unsubtle, but I guess it wasn't so bad after all.