Specifications

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9.1 Overview
BHT-BASIC supports event polling and two types of trapping: error trapping and event trap-
ping.
■ Event Polling
Makes programs monitor the input devices for occurrence of events.
■ Error Trapping
Traps a run-time error and handles it by interrupt to transfer control to the error-handling rou-
tine.
If a run-time error occurs when this trapping ability is disabled, the Interpreter will terminate the
current user program while showing the error message.
■ Event (of Keystroke) Trapping
Traps a particular keystroke (caused by pressing any of the specified function keys) and han-
dles it by interrupt to transfer control to the event-handling routine.
– Event polling
– Trapping Error trapping
Event (of keystroke) trapping