This command is only legal on the IEEE-488 interface. If the computer is the system controller but not the active controller, ABORT causes the computer to assume active control.
If a primary address is specified, an error is generated. If the computer is the system controller, the bus action is to issue IFC for greater than 100 micro-seconds and then to assert REN and de-assert ATN. If the computer is not the system controller but is the active controller, the bus action is: ATN, MTA, UNL and de-assert ATN. If it is also not the active controller, no action is taken.