My friend James Thomson is celebrating the 30th anniversary of PCalc, his calculator app:
The built-in Mac OS calculator of the day was a very simple affair, and so I decided I would write a calculator that could do binary and hex, to help me with my programming. And so the idea for PCalc was born. I bought the books Inside Macintosh, Volumes I, II, and III, and sat down to figure it all out. We didn’t have the Internet back then – well, no web at least – so that was basically all I had to go on. Eventually, I started to get the internal logic working, and built a user interface around it all. System 7 was new, so I eventually got a copy of the massive Volume VI to see what had changed there. I didn’t think I needed any of the stuff in the middle.
In its life PCalc has been many different code bases, lived on a huge number of Apple platforms, and gone from being just for fun to a major moneymaker to a low priority to the highest priority to an incubator for a driving game. A lot can happen in thirty years.