NSD Editor

The Nassi-Shneiderman area-subdividing flowchart lent itself to calligraphic displays and the interactions they enabled. I wrote such an editor over a semester with only 20 minutes a week access to the machine for debugging.

From Technical Contributions, Sigplan Notices, 1973.

I coded in fortran through the week checking for syntax errors with compile-only runs on the campus computer. I cross-compiled to the Imlac PDS-1 with a locally developed compiler that only ran on the co-located PDP-11. Compilation took the better part of my one hour reservation. It was slow but it never let me down.

I approached each week with specific coding and learning goals in mind. I was building an interactive tool and had to assess my success by interacting with it. I also designed program diagnostics that could show how and why the program behaved as it did by selectively printing internal state in response to keypad requests.