Keeping stuff: How to preserve course papers despite technological change

Teletypes and tape punches

In 1970, I took a course in which we used a computer. Not that any of us actually got to see the computer, of course; we used it by remote control, sitting at a teletype machine at the University of Chicago and sending signals by telephone to a branch of the General Electric Company downtown, several miles away. This is part of the record of one of my early sessions, dated January 20, 1970. It includes solutions to three simple problems, each of which involved writing a short program in the BASIC programming language.

This paper was fed through the teletype's printing mechanism as I worked. The underscore in line 40 records my decision to cancel the double quotation mark that precedes it. This operation removed the unwanted character from the communication channel before it was transmitted to the computer, but there was no way to erase it from the printed record. Thus I could edit my programs as I worked on them, but all of my editing was visible in the transcript.

Although the transcript requests a ``file name'' for each program, this was just a figure of speech, describing the structure of the workspace during a session. We were not permitted to save programs in persistent storage on the computer that we used, so that they could be recovered in subsequent sessions. At first, I did the problems by actually typing in every program I needed, each time I needed it.

Eventually, however, I learned that one could record one's programs on inch-wide paper tape, using a tape punch mounted on the teletype machine. Each character and control operation corresponded to a pattern of holes across the width of the tape. A program like this one would require only a foot or two of tape, but eventually I wrote programs that were yards long. The advantage was that the tape punch could also be used as a reader, so that by feeding in an already-punched tape and pressing a button, one could have the device type in the recorded program for you, usually without error unless the tape had been folded or otherwise damaged. The hole patterns did not correspond in any obvious way to the characters they encoded, so it was not ``human-readable.''

I no longer have any of the paper tapes that I punched in 1970. After the course ended, I was never again in the presence of a device that could either make them or read them, and they were fragile enough that, even if the tape reader was available, it is unlikely that the tape could still be read accurately. It is likely that I lost some of the programs that I wrote, since I didn't keep all of my session transcripts in hard copy, either.