The Instructograph was a
paper tape
Five- and eight-hole punched paper tape
Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program loop
Punched tape or perforated paper tape is a form of data storage ...
-based machine used for the study of
Morse code
Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of ...
.
The paper tape mechanism consisted of two reels which passed a paper tape across a reading device that actuated a set of contacts which changed state dependent on the presence or absence of hole punches in the tape. The contacts could operate an audio oscillator for the study of
International Morse Code
Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of ...
(used by radio), or a sounder for the study of
American Morse Code
American Morse Code — also known as Railroad Morse—is the latter-day name for the original version of the Morse Code developed in the mid-1840s, by Samuel Morse and Alfred Vail for their electric telegraph. The "American" qualifier was added ...
(used by railroads), or a light bulb (
Aldis Lamp
Signal lamp training during World War II
A signal lamp (sometimes called an Aldis lamp or a Morse lamp) is a semaphore system using a visual signaling device for optical communication, typically using Morse code. The idea of flashing dots and da ...
- used by Navy ship to ship or by
Heliograph
A heliograph () is a semaphore system that signals by flashes of sunlight (generally using Morse code) reflected by a mirror. The flashes are produced by momentarily pivoting the mirror, or by interrupting the beam with a shutter. The heliograp ...
).
The Instructograph was in production from about 1920 through 1983. The first US patent, No. 1,725,145, was granted to Otto Bernard Kirkpatrick, of Chicago, IL, on August 20, 1929. Most of them would be wound by hand or be plugged into a wall outlet. Most plugin outlet based instructographs would have a set of knobs that can control the speed and volume. The latest version of the Instructograph was the model 500 which included a built in solid state oscillator. This model was available to be purchased as new through at least 1986.
External links
Instructograph advertisement, ca. 1950
History of telecommunications
Morse code