The error code displayed on line 25 of a {IBM 3270} {terminal} (or a {terminal emulator} emulating a 3270) for various kinds of protocol violations and "unexpected" error conditions (including connection to a down computer). On a PC, simulated with "->/_", with the two centre characters overstruck. "Broken arrow" is also military jargon for an accident involving nuclear weapons. [Jargon File] (1995-02-07)