Teletype Model 28
| Teletype Model 28 | |
|---|---|
| Manufacturer | Teletype |
| Model | Model 28 |
| Lifetime | |
| Introduced | 1951 |
| Discontinued | 1960 |
| Communication | |
| Interface | 60 mA current loop |
| Baud Rates | 45.5, 50, 56.9, 74.2 |
| Character Modes | |
| Attributes | Normal |
The Teletype Model 28 was introduced in 1951 and designed to be used in continuous operation, being of very rugged construction. It used 5-level baudot code for communication over a current loop interface. It was also available in a receive only (RO), and automatic send/receive (ASR) configuration.[1]
The Model 28 was developed for the U.S. Military, with the first typing unit delivered to the Navy in 1951; commercial release followed in 1953.[2] The equipment was designed for 100 words per minute (wpm) operation, requiring less maintenance than the preceding Model 15 line.[2] Operating speeds of 60, 75, or 100 wpm are determined by the gear set installed on the motor unit.
A central component of the Model 28 is the "stunt box," a mechanical sequential selector. It monitors the incoming signal and triggers non-printing functions such as carriage return or line feed when specific character sequences are detected.[3] The printing mechanism uses a compact, interchangeable type box instead of a traditional typebar basket. This box shifts vertically and horizontally to align characters with a single printing hammer, improving reliability in mobile or vibrating environments.[2]
Standard configurations include the Keyboard Send-Receive (KSR) set, consisting of a keyboard, page printer, and motor unit. Floor-standing cabinets weigh approximately 130 pounds and typically utilize a 115 VAC 60 Hz synchronous motor.[4]
References
- ↑ "TELETYPE MODEL 28 PAGE PRINTER". http://www.baudot.net/teletype/M29.htm. Retrieved Februrary 18, 2020.
- ↑ "Teletype Stunt Box - Southwest Museum Of Engineering". https://smecc.org/teleprinters/28stuntbox001.pdf. Retrieved February 26, 2026.
- ↑ manual
