I started my career in 1970 as a Co-Op Student at McDonnell-Douglas in St. Louis, while working toward a double major in Electrical Engineering and Computer Science at the University of Missouri – Rolla.
For my third work period, after my Sophomore year, I was assigned to a Radar Simulation facility working with my first mini-computer – a Datacraft Slash 4 (Google it – you might find something at the Computer History Museum).
On my first day, my Supervisor, Jim, asked me what I knew about programming in Assembly Language. I said, “Nothing.” So, he asked, “What do you know about how computers work?” Not wanting to appear too inexperienced I replied with what I knew about Basic and Fortran programming. “That’s good, but how about what actually goes on inside the computer?” Again, I had to say, “Nothing.”
Jim pulled out a fresh pad of paper and a sharpened pencil and drew the symbol for a transistor. “What’s that?” he asked. “A transistor,” I replied.
And with that he started building NAND gates, flip-flops, and registers. Adding a clock and a discussion of 2’s complement binary arithmetic, he went on to build an accumulator, comparator, a multiplier, and ultimately, a rudimentary CPU.
Putting his first pad of completely used pages aside, he moved on to magnetic core memory, sense lines, read/write lines, hardware buses, and indexers. Then with another fresh pad, we started looking at disk drives, interfaces, and boot loaders. And finally, to complete the picture up to where I had started, we discussed language interpreters and compilers.
It was a long, hard day.
But I learned more about computers in that one day than I would have learned in an entire semester of classes on campus.
The next morning, I started writing the first of several programs I wrote during that assignment – a symbol cross-reference utility for Datacraft assembly language programs, written in Datacraft assembly language. Later on, I wrote another utility, this time in Fortran, to calculate the straight-line distance between an aircraft in flight, and a series of ground-based radar installations.
To my credit, I discovered a bug in the Fortran compiler and helped Jim to fix it. Then, to my dismay, as he was winding up several miles of paper tape he had just punched, I stepped on it and broke it!
We remained good friends for quite some time after I graduated, and I saved that stack of paper for quite some time as well. Jim remains my inspiration and motivation for giving back to others, the way he gave to me nearly 50 years ago!
