One of my fondest memories of Mac involves his beloved project, V'GER.
It was originally posted by a casual visitor with the handle GIBBERISH who needed a little help. Mac gave it to him, and in so doing, managed to rewrite the program several times. Well, GIBBERISH never came back (Mac later discovered that he had died) but the game became Mac's passion for well over two years.
The reason the memory is so sweet to me, is that I often had the idea that Mac always wanted to create a truly great game program, but for whatever reason, could never quite manage it. With V'GER, he sort of had his chance. I have to smile whenever I go to the V'GER page and see all the revision posts.
Mac was always full of praise for my programs, but in a way, his efforts were more laudable than mine because he worked so hard at it -- wanted it so badly. I never came even close to beating his high score, but whenever I would try out the latest V'GER revision, I had to smile; Mac's enthusiasm and dedication were written all over it.