Teletype Model 37

The Teletype Model 37 is an electromechanical teleprinter manufactured by the Teletype Corporation in 1968.^[1] Electromechanical user interfaces would be superseded as a year later in 1969 the Computer Terminal Corporation introduced the electronic terminal with a screen.

Teletype Model 37. On display at the Living Computer Museum in Seattle, Washington.

Features

The Model 37 came with many features including upper- and lowercase letters, reverse page feed for printing charts, red and black ink, and optional tape and punch reader. It handled speeds up to 150 Baud (15 characters/second). This made it 50% faster than its predecessor, the Model 33.^[1]

The Model 37 terminal utilizes a serial input / output 10 unit code signal consisting of a start bit, seven information bits, an even parity bit and a stop bit. It was produced in ASR (Automatic Send and Receive)also known as the Model 37/300, KSR (Keyboard Send and Receive) also known as the Model 37/200 and RO (Receive Only) also known as the Model 37/100.^[2]

The Model 37 handles all 128 ASCII code combinations.^[3] It uses a six-row removable typebox with provisions for 96 type pallet positions. When the Shift-Out feature is included, the six-row typebox is replaced with a seven-row typebox allowing 112 pallet positions, or it can be replaced with an eight-row typebox allowing 128 type pallet positions.

Technical specifications

• The Model 37 RO and KSR are 36.25 inches high, 27.5 inches deep and 22.5 inches deep. The ASR is 36.25 inches high, 44.5 inches wide and 27.5 inches deep.^[2]
• The ASR weighs approximately 340 pounds and KSR and RO weighs approximately 185 pounds.^[4]
• The Model 37 interface meets the requirements of EIA RS-232-B and has a recommended maintenance interval of every six months or every 1500 hours.^[3]
• Power Requirements - 115VAC ± 10%, 60 Hz ± .45 Hz, RO is approximately 200 Watts, KSR is approximately 300 Watts, ASR is approximately 550 Watts.^[2]

Fun Facts

• Most Model 37s were re-purchased from customers and sold to the Soviet Union with antiquated mainframe computer systems.^[1]