My Calculator Story

The slide rule - from 7th grade to …


I’m not sure at all how I knew of slide rules. My parents never had one. I never saw one in any of my elementary classrooms. Maybe it was from watching the televised early manned space flights? But somehow I got it in my head that I wanted a slide rule, and when I was in the 7th grade I used my allowance to buy a 6-inch plastic Sterling slide rule from the local drug store for $1.


It came with a small one sheet set of instructions, printed in absolutely tiny print. I went through it and through it and I remember being really frustrated at first at not being able to get it to work, but eventually there was a breakthrough and I mastered all the available scales. It felt good, but anticlimactic, and I was a little surprised when I found my parents and grandparents super impressed and bragging about me.


By the 9th grade or so I was the student showing others how to use the tool. It was an essential skill for HS chemistry and physics in the 60’s, basically a requirement if you wanted to get a test completed in the time available. I think by then I had a nice metal Pickett slide rule. I remember the first day of one of my college physics classes one of my professors even gave us all a “slide rule drill,” that is, he shouted out problems and we all raced to see who could get the answer first. Using a slide rule was a requirement to doing science.

A first sighting of the first handheld scientific calculator, the HP-35…


In the spring of 1972 I left my slide rule in a physics lab one day, and like leaving your iPhone in a coffee shop today, it was gone immediately. I needed it for survival in every class, so I went to the college bookstore to replace it. They had a nice display of slide rules in a glass case, but on top of the counter was something I’d never seen before, a handheld calculator, the HP35. I played with the calculator for a long time and was absolutely blown away. But at $395, vs. something like $20-30 dollars for a nice slide rule, and living in the innocent poverty of a student, there was just no way that was going to happen. I went back to my dorm room with an upgraded slide rule, a nice K&E with a leather case.


I was happy with my K&E, but the calculator experience really stuck with me. The biggest take away wasn’t only that I wanted that calculator, but that I was mystified about how the calculator worked. As a student majoring in physics for the explicit reason that I wanted to understand how The Universe worked (yes, I was young), not understanding was completely unacceptable. I immediately added understanding computer hardware to my list of things to do, and started working on it in my spare time.


I finally got my first calculator when I was in grad school, an HP-25. And I have been an HP fan ever since, pretty much always owning their top of line model from my first job up to today.

Computers, Software, Hardware… and my life…


In 1968 my high school district bought a mainframe computer to do payroll. It occupied several rooms in district headquarters. Since it was sitting unused most of the time, someone got the idea to teach a programming class to HS kids. No one knew how to program, but the HS chemistry teacher volunteered to teach the class and the teacher and class of about 10 budding geeks all learned to program together. We had a key punch in a closet, and every day someone would drop off our decks of cards in the evening and pick up our stacks of computer-fold printouts in the morning. I kind of joke that in that one semester HS class doing Fortran, I learned more about computers than in any class since then. I was a programmer, but the computer was far away, out of sight, and I didn’t think much about it. When I look back, I realize how incredibly privileged I was to have a HS programming class then.


I did a little Fortran programming in college to support my physics, but it wasn’t my favorite thing. The calculator moment came and went. But then, in graduate school, I found that we had a Digital Equipment PDP-8 in a closet. It had a paper tape reader and a teletype, and I was hooked immediately. It was so fun to have a computer that you could actually interact with. This was 1974 and by 1975 I was daydreaming with friends about building a home computer. Job prospects were not abundant. While living in Eugene, Oregon, I saw an advertisement in the Portland newspaper for a technician job at Intel. I applied mostly because I was excited about getting a tour of the plant, and was amazed when they offered me a job.


I worked for 40 years in the semiconductor industry, finding my way to my beloved home in the the beautiful Santa Clara valley. I worked on many technologies and IC’s, and was exposed to many types of digital and analog products, and many kinds of programmable architectures. I was always more of a hardware guy, but nowadays nothing can be done without some software expertise, so I learned every new language that came along. The biggest thing though was that I never stopped using programming as a tool to solve whatever problem was in front of me.

At the cusp of the digital age…


I realize in my work with today’s generation of young people and students that I was lucky to be around and to track closely the transition of the world from the old to the new. I joke with the younger generations that learning computers was super easy for me because I only needed to learn one little thing at a time! Kids today need to master it all in a few years.


Folks my age lived through the age from slide rules to the first mainframes to our current handheld computers (phones), powerful desktops, and the internet. It is surprising and wonderful, and I am fortunate to have witnessed this historical transition. The accident of my birth at that particular time has given me a unique perspective and appreciation of the digital age.

Final twist of fate… the TI-84 calculator…


After I stopped working in the Silicon Valley semiconductor industry, I started tutoring math and physics to high school students. All my students use TI-84 graphing calculators, a really powerful tool that is much taken for granted. Although I’m still a died-in-the-wool HP user, I bought one myself so that I could help my students. One day on a whim I searched for TI-84 on Wikipedia, and I found that it’s CPU is based on the EZ80 core, a core with a history that goes back to the 70’s. I recalled that TI had been a customer of mine when I worked for Zilog, and I had actually supported them with my compiler team. I worked on other versions of the chip and IP for many customers. So I can say I worked on the chip that goes into all my students’ calculators!

My current selection.