IBM 3270 PC
Encyclopedia
The IBM 3270 PC 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.
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 scancode
s 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.
Terminal emulator
A terminal emulator, terminal application, term, or tty for short, is a program that emulates a video terminal within some other display architecture....
the behaviour of an IBM 3270
IBM 3270
The IBM 3270 is a class of block oriented terminals made by IBM since 1972 normally used to communicate with IBM mainframes. As such, it 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...
terminal. It could therefore be used both as a standalone computer, and as a terminal to a mainframe
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
.
IBM later released the 3270 AT (model 5281), which was a similar design based on the IBM PC AT.
Technology
The additional hardware occupied nearly all the free expansion slots in the computer. It included a video cardVideo card
A video card, Graphics Card, or Graphics adapter is an expansion card which generates output images to a display. Most video cards offer various functions such as accelerated rendering of 3D scenes and 2D graphics, MPEG-2/MPEG-4 decoding, TV output, or the ability to connect multiple monitors...
which occupied 1-3 ISA slots (depending on what level of graphics support was required), and supported CGA
Color Graphics Adapter
The Color Graphics Adapter , originally also called the Color/Graphics Adapter or IBM Color/Graphics Monitor Adapter, introduced in 1981, was IBM's first color graphics card, and the first color computer display standard for the IBM PC....
and MDA
Monochrome Display Adapter
The Monochrome Display Adapter introduced in 1981 was IBM's standard video display card and computer display standard for the PC. The MDA did not have any pixel-addressable graphics modes...
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 scancode
Scancode
A scancode is the data that most computer keyboards send to a computer to report which keys have been pressed. A number, or sequence of numbers, is assigned to each key on the keyboard.- Variants :...
s 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
- 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.