| 摘要 |
<p>In a display termina! coupled to a computer and including a plurality of user interrupt devices for interactive communication with the computer, an apparatus for signalling to the user when the computer responds to a user interrupt comprises a counter (20) arranged to measure a specified period of time by counting down to zero from an initial count value loaded from a register (21), a sensor (14) triggered by the generation of an interrupt to cause the counter (20) to begin measurement of the said specified period of time (21), and a further sensor (15) coupled to an alarm (23) via a logic gate (24) to provide an audible signal only when the period of time between the generation of the interrupt and the computer response exceeds the specified period of time measured by the counter.</p> |
