Dumb terminals at Stanford

In 1976 (before home computers became available) I bought an ADM-3 ASCII terminal kit. The terminals were meant to be educational and workplace tools: a way of connecting students and system programmers, such as myself, with the mainframes at Stanford University and the Stanford Linear Accelerator Center (SLAC), where I worked. SLAC arranged for us to purchase the terminals at a discount.

ADM-3 terminal
ADM-3 terminal

The kit had over 2000 solder joints and took many hours to complete. When it was finally working, I could log on to the SLAC computer from home using a 300-“baud” (30KB) acoustic coupler modem. Now people think 50KB is slow! Primitive as it was, this terminal saved me many trips to SLAC to fix problems.

However, in our household (and in many others in the Bay Area computer community), the terminal was quickly co-opted by the family teens and preteens for game-playing, which was also pretty primitive at the time!

Above is a picture taken in the late 70s of my daughter Ellen playing a Star Trek game while logged on to the SLAC computer.

The ADM-3 was what was known as a “dumb terminal.”  The display held 24 lines of 80 column text. It had no graphics capability. Imagine playing a game called “Star Trek” (another popular one was “Adventure”) with no graphics! The player had to imagine the background scene (for example, a cave), and who or what was there. Instructions to the computer and the resulting actions (if any) were typed in text.

For example, if the player wandering through the cave had just found a magic lamp, her instructions to the computer might be “Rub the lamp.” The computer might respond with “A door opens.” A common response, which was very frustrating to players, was “Nothing happens.”

In early 1977 Lear Siegler sold the ADM-3 as both a completed terminal and also as a “do-it-yourself” kit. By the end of 1977 the first personal computers began to appear on the market and people started to lose interest in having only a terminal at home.

“Vintage” ADM-3s still exist today. Below is a picture of one stored in the Computer History Museum archives (Mountain View, California), where I saw it in 2014, when I was cataloging artifacts.

ADM-3 terminal in the Computer History Museum collection
ADM-3 terminal in the Computer History Museum collection

Author: Dick

Principal and technology specialist, VR Communications LLC