TEC 440
| TEC 440 | |
|---|---|
 | |
| Manufacturer | TEC |
| Model | 440 |
| Lifetime | |
| Introduced | June, 1972 |
| Introductory Price | $2,245 |
| Communication | |
| Interface | RS-232C |
| Baud Rates | 110-9600 |
| Display | |
| Size | 12-inch |
| Refresh Rate | 60 Hz |
| Character Modes | |
| Resolutions | 80x24, 72x24 |
| Matrix | 5x7 |
The TEC Model 440 DATA-SCREEN is a "fourth-generation" asynchronous CRT computer terminal manufactured by TEC, Incorporated of Tucson, Arizona. Formally introduced in June 1972, the Model 440 was designed as a high-reliability, solid-state alternative to mechanical teleprinters, providing a plug-compatible replacement for the Teletype Model 33 and Teletype Model 35 KSR units.[1]
Contents
Design and Hardware
The terminal features a 12-inch (diagonal) cathode-ray tube with a high-contrast bonded-glass faceplate. The display logic generates a 64-character ASCII set using a 5x7 dot matrix. A defining hardware feature of the Model 440 is its switch-selectable line length, allowing for either 72 or 80 characters per line across a 24-line display. [2]
Internally, the Model 440 utilizes modular printed circuit boards for timing, memory, and character generation. It supports asynchronous serial communication via an RS-232C interface at baud rates ranging from 110 up to 9600. The memory architecture consists of 1,920 character MOS shift-register storage. The unit also features an auxiliary 9-pin connector to drive an external Receive-Only (RO) printer for hard-copy requirements.
Functional Features
To minimize software overhead for users transitioning from mechanical systems, the Model 440 employs specialized display logic to simulate Teletype-style input/output. The terminal was notably marketed for its ability to handle dual-speed data flows to optimize CPU efficiency during transmission.
The unit mimics the paper-feed behavior of a physical teleprinter by utilizing the bottom line of the screen for data entry, with existing text scrolling upward. Additionally, built-in logic provides automatic carriage return and line feed, preventing the "end-of-line hang-ups" common in older mechanical systems.[3]
History
Introduced at a price of $2,245, the Model 440 was positioned as a premium "electronic teletype" intended to reduce maintenance costs and noise in time-sharing and minicomputer environments. [4] Its rugged design and "handsome styling" were hallmarks of TEC's DATA-SCREEN Series 400 family.
Manx
- Teletype Replaceable Data-Screen Terminal Model 440 Product Description, October, 1972
- TEC Data-Screen Terminals Reference Drawings Model 440, September, 1974
Images
References
References
- ↑ [https://manx-docs.org/details.php/ 111,18397 Teletype Replaceable Data-Screen Terminal Model 440 Product Description ]
- ↑ "Tec CRT Handles Dual Speed Data Flow to Optimize CPU", Computerworld, June 28, 1972, pg. 12
- ↑ "TEC DATA-SCREEN Terminals (Advertisement)". Datamation. Technical Publishing Co.. November 1972. pp. 33-40. http://www.bitsavers.org/magazines/Datamation/197211.pdf. Retrieved February 24, 2026.
- ↑ "Looking back at the Series 400", InfoWorld, August 31, 1981, pg. 44
