Sunday, April 22, 2007

Computers in Schools in the 1970s

I wrote the following for a history page in a wiki on school computing:

I was a student at Concord Academy, graduating in 1973. As best I can remember it was fall of my senior year when we got access to a computer. We had one teletype connected to a timesharing service running on a PDP-8/I. I remember that the for-profit company providing the service had about twice as many schools connected to timesharing system as the system was supposed to accomodate. But remember we were communicating with the computer by a teletype--a large machine with a typewriter keyboard and a roll of paper. There was no screen of any kind--what you typed appeared on the roll of paper and then when you typed "run" the machine would type the results of your program onto the same roll of paper. There was a way to store your program, on paper tape with holes punched in it. A device on the side of the teletype punched this tape and also read it.

Since the interface was so slow the speed of the computer wasn't usually noticeable. But someone at another school wrote and shared a program to calculate pi to the limits of core memory, and that would slow the machine down noticeably. I remember the output of that program being maybe three feet of paper--the limits of core wasn't very much (online sources suggest it would have been 4 kilowords).

We learned to write programs in BASIC, which didn't seem very significant. A friend and I were the two people who hung around and played with the computer. The only next step we could figure out was to learn assembly language. We decided to try to write a lunar lander text-based game in assembly language. We got Miss Plumb, the Chemistry teacher, to let us do it as one of the units of a course in advanced biology and chemistry (in another unit we bred fruit flies). All the text that was going to appear in the game had to be translated into numeric form using ascii code--we hired a younger student to do that. But we never could get our program to work fully. I remember telling Miss Plumb that we hadn't solved all the problems yet and she said she had already submitted our grades. I still feel guilty that we didn't live up to her faith in us and finish it.

It didn't occur to me to take a computer course when I got to college; I was planning on majoring in astronomy and physics (I later ended up in history of science and technology). After my sophmore year of college I got a job working for an astronomer compiling some data and writing a program in Fortran to analyze it. I knew nothing about Fortran but I don't remember having any hesitation about going out and learning it on my own. That was batch processing--punch cards for input and then when the computer got to the job you had submitted the results would appear on a printer.


Shazam! said...

WOW, I wrote a lunar landing game too!!! except it was in basic. We learned the equation for gravity in an after school session, and we knew how to make shapes, so we made a lunar lander game. you had to fire the engines to slow down your descent and land the lander without goingg to o fast or else it would crash. We wrote original music for the game. We were disqualified in a contest because the judges didn't think that 6th graders could write something that good. I'm still bitter about it!

Pem said...

That's how ours was supposed to work too! No music, though. In what year were you writing yours? Really unfair that the judges disqualified you. Were you a mixed group or was it also that they didn't think girls could do it?