This was my first non-human opponent:
I used to lose hundreds of games at the lowest level when I was around 14, until I started winning. It was so horrible at the endgame that I once won a piece down, B+Ps vs Ps. And I used to consider a kingside attack a cheap way to win against it. I moved up the levels and eventually would play games that lasted for days on its 25 minute per move level, but I could always win easily at this point. Around this time I started going to a chess club, and my first established rating was low 1300s.
I also had some chess programs for my TRS-80:
Microchess
Z-Chess
Sargon II
(I forgot how bad the graphics were)
Also had some C64 programs: