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| Type | Personal computer |
|---|---|
| Release date | October 1983 |
| Discontinued | 1987 |
| Operating system | IBM BASIC / PC-DOS 2.0 |
| CPU | Intel 8088 @ 4.77 MHz |
| Memory | 256KB ~ 640KB |
The IBM 3270 PC (model 5271), released in October 1983, was an IBM PC XT containing additional hardware which could emulate the behaviour of an IBM 3270 terminal. It could therefore be used both as a standalone computer, and as a terminal to a mainframe.
IBM later released the 3270 AT (model 5281), which was a similar design based on the IBM PC AT.
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Technology [link]
The additional hardware occupied nearly all the free expansion slots in the computer. It included a video card which occupied 1-3 ISA slots (depending on what level of graphics support was required), and supported CGA and MDA video modes. The display resolution was 720×350, either on the matching 8-color monitor (model 5272) or in monochrome on an MDA monitor.
A further expansion card intercepted scancodes from the 122-key 3270 keyboard, translating them into XT scancodes which were then sent to the normal keyboard connector. The final additional card provided the communication interface to the host mainframe. Please note that the 3270 PC pictured above has an original PC keyboard attached and not the 122-key 3270 keyboard.
Models [link]
- 3270 PC (model 5271) - original 3270 PC
- 3270 PC/G - 3270 PC with improved graphics hardware and mouse support
- 3270 PC/GX - Extended graphics support; 19-inch color or monochrome monitor.
- 3270 AT (model 5281) - corresponds to the 3270 PC, but based on an IBM AT.
- 3270 AT/G - corresponds to the 3270 PC/G, but based on an IBM AT.
- 3270 AT/GX - corresponds to the 3270 PC/GX, but based on an IBM AT.
See also [link]
External links [link]
https://wn.com/IBM_3270_PC
IBM 3270
The IBM 3270 is a class of block oriented computer terminal (sometimes called display devices) introduced by IBM in 1971 normally used to communicate with IBM mainframes. The 3270 was the successor to the IBM 2260 display terminal. Due to the text colour 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.
Although IBM no longer manufactures 3270 terminals, the IBM 3270 protocol is still commonly used via terminal emulation to access mainframe-based applications. Accordingly, such applications are sometimes referred to as green screen applications. The use of 3270 is slowly diminishing as more and more mainframe applications acquire Web interfaces, although some Web applications merely use the technique of "screen scraping" to capture old screens and transfer the data to modern front-ends.
