A 3270 Emulator is a computer program that duplicates the functions 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...

 mainframe computer terminal

Computer terminal

A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...

 on a PC

Personal computer

A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

 or similar microcomputer

Microcomputer

A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...

.

As the original 3270 series terminals were connected to the host computer using coaxial cable

Coaxial cable

Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...

, emulators required coax adapter cards to be installed in the PC. Today, many emulators communicate with the mainframe computer

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...

 through the TN3270 variant of the Telnet

TELNET

Telnet is a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communications facility using a virtual terminal connection...

 protocol common on TCP/IP networks including the Internet

Internet

The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

, so special hardware is no longer required.

Products

In 1983, IBM marketed the IBM 3270 PC

IBM 3270 PC

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...

, a bundled package including a PC, 3270 emulation software and coax interface card. 3270 emulators are also available from many third-party vendors like Attachmate

Attachmate

Attachmate Corporation is a software company owned by an investment group led by Francisco Partners, Golden Gate Capital, and Thoma Cressey Bravo. Attachmate focuses on terminal emulation, legacy modernization, managed file transfer, and enterprise fraud management software. Attachmate Corporation...

 and Ericom. Some solutions permitted a coax interface to be shared by workstations in a LAN.

See also

• Irma board
  Irma board
  Irma board, originally spelled IRMA board, refers to a brand of coaxial interface cards for PCs and Macintosh computers used to enable 3270 emulator programs to connect to IBM mainframe computers....
  
  
• Terminal emulator
  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....
  
  
• Systems Network Architecture
  Systems Network Architecture
  Systems Network Architecture is IBM's proprietary networking architecture created in 1974. It is a complete protocol stack for interconnecting computers and their resources. SNA describes the protocol and is, in itself, not actually a program...
  
   (SNA)
• Synchronous Data Link Control
  Synchronous Data Link Control
  Synchronous Data Link Control is a computer communications protocol. It is the layer 2 protocol for IBM's Systems Network Architecture . SDLC supports multipoint links as well as error correction. It also runs under the assumption that an SNA header is present after the SDLC header...
  
   (SDLC)
• TN3270 Plus
  TN3270 Plus
  TN3270 Plus is a 3270 terminal emulator. TN3270 Plus is one of the widely used Telnet terminal emulators. TN3270 Plus is used for connecting Windows PC users to IBM mainframe, AS/400 and UNIX systems via TCP/IP...