The IBM 3270 is a family of block oriented display and printer computer terminals introduced by IBM in 1971 and normally used to communicate with IBM mainframes. The 3270 was the successor to the IBM 2260 display terminal. Due to the text color on the original models, these terminals are informally known as green screen terminals. Unlike a character-oriented terminal, the 3270 minimizes the number of I/O interrupts required by transferring large blocks of data known as data streams, and uses a high speed proprietary communications interface, using coaxial cable.
IBM 3277 Model 2
Sample IBM 3270 cluster with one control unit connected to a printer and two displays
IBM selector-pen in use
3278 terminal
A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. The teletype was an example of an early-day hard-copy terminal and predated the use of a computer screen by decades. Starting in the mid-1970s with machines such as the Sphere 1, Sol-20, and Apple I, terminal circuitry began to be integrated into personal and workstation computer systems, with the computer handling character generation and outputting to a CRT display such as a computer monitor or, sometimes, a consumer TV.
A Teletype Model 33 ASR teleprinter, usable as a terminal
Closeup of an IBM 2741 printing terminal, which used a changeable Selectric "golfball" typing element and was faster than the earlier teletype machines
IBM 2260
ADM-3A