The Computer Behind the Scenes
An inexperienced person using the Dartmouth Time-Sharing System might think of the terminal they were typing into as the computer itself, and this was intentional. The large, powerful computer that was the core of the DTSS stayed mostly out of sight and out of mind, allowing users to feel less intimidated and more free to experiment. But while the average user could ignore the hardware, finding a computer that could handle the demands of time-sharing was the key to pulling off the DTSS experiment in the first place, and that wasn’t so easy. Fortunately, a pair of computers from General Electric—one to communicate with the teletypes, and one to run the programs—was able to get the job done.
A Preliminary Proposal for Dartmouth College, Hanover, New Hampshire
Thomas Kurtz and Anthony Knapp ’63 originally approached GE hoping they would donate a computer for the time-sharing system. Although GE declined to give away a free computer, they agreed to sell it at a discount, and so the GE-225 became the first DTSS computer.
Letter of Intent – Purchase
This page lists only some of the equipment that Dartmouth purchased from GE to build the original time-sharing system. The full invoice added up to $441,762, which equates to about $4.2 million in 2022—and that’s not including the monthly maintenance charges!
DTSS-2 motherboard
This motherboard was part of the second version of the DTSS, which was developed in the late 1960s and used a newer GE-635 computer.
New General Electric Arriving
Especially in the first few years in the DTSS, the equipment would be periodically replaced with newer technology. (The equipment in this image was probably part of the original DTSS setup in 1964.)
Honeywell system console(?)
General Electric sold its computer division to Honeywell in 1970, so this part could date from the 1970s or later.
