We’ve all received that handwritten note in the mail for new windows, only to realize it was printed from a computer. Advertisers have long striven to produce personalized content, including in the early 1900s with the automatic electric typewriter. Rather than print a form letter using a typewriter font and then physically typing so-and-so’s name into the copy, this machine typed the entire letter.
The Automatic Underwood Typewriter Operator featured in Railway World (above) and Popular Electricity (below) could churn out between 7,000 and 10,000 words per hour.1 Designed and patented by Lyman R. Roberts and Charles L. Davis in 1914, the bulk letter writer was assigned to Underwood (US1109597A).
Ingeniously, it was “programmed” using perforated sheets: one containing form copy and another with individualized matter. It operated under the same principles as a player piano. Based on the earliest patent, development on the machine began sometime before 1908.
A second machine for creating the master sheets was patented in 1910 (US953180A), and subsequently improved in 1915 (US1160101A). Further patents for both devices followed.
In 1912, the Star Clothing Company of New York was among the first to employ the device.2 How widely it circulated is uncertain. There are only a few references to the machine in searchable databases.
The Underwood machine employed perforated sheets to activate the typing, much like a player piano. The image is from the patent.
From the patent:
“The machine hereinafter described is provided with means for producing the actuation of the several parts of the typewriter from either of a plurality of control sheets, or master-letters, (using this term to mean a perforated sheet which acts to control the various movements of the movable parts of the machine.) One of these so-called master-letters contains perforations which control the writing of the body of a letter, and another so-called master sheet contains the controlling means for insets that, are inserted in the main writing. To make this clear, suppose it be desired to write a large number of letters, each of which contains the same text, but each of which is ad dressed to a different individual, or in some of which there are to be insets containing matter that is not contained in other letters.”
From Popular Electricity, December 1911 –
© 2026, Mark Adams. All rights reserved.
There were also other such player-piano-like devices, such as the post-WWII Friden Flexowriter, based on an IBM.
That’s an interesting machine. I wonder if anyone collects them.