# c3270 Introduction

c3270 is a curses-based IBM 3270 terminal emulator. It can be used to communicate with any IBM host that supports 3270-style connections over TELNET. It can also communicate with hosts that use line-by-line ASCII mode to do initial login negotiation before switching to full-screen 3270 mode.

c3270 emulates one of four models of an IBM 3278 or 3279 terminal. The difference between the various models is the screen size. The emulation is not quite complete; c3270 understands extended field orders but does not implement some of the extended attributes (outlining, extended validation, etc.).