Texas Instruments TI-89 Developer's Manual page 672

630
idle
(continued)
if ( !OSTimerExpired( APD ) && !OSTimerExpired( USER ) && !kbhit() )
idle(); /* Stop CPU, but keep LCD alive . . . save power */
}
if ( OSTimerExpired( APD ) ) {
off();
OSResetTimer( APD );
continue;
}
if ( OSTimerExpired( USER ) )
i = EX_TIMEOUT;
if ( kbhit() )
switch ( i = ngetchx() )
case KB_ON+KB_OPTION:
i = EX_OPT_OFF;
off();
break;
case KB_OFF:
i = EX_2ND_OFF;
off();
break;
default:
i = EX_KEY;
pushkey( i );
}
OSResetTimer( APD );
}
if ( OSOnBreak )
i = EX_BREAK;
if ( !i )
continue ;
else {
OSFreeTimer( USER );
return i;
}
} //while ( TRUE )}
TI-89 / TI-92 Plus Developer Guide
Appendix A: System Routines — Interrupts
/* if the APD timer went off */
/* turn the calculator off until they turn it on */
/* reset APD */
/* go back to looking for keys */
/* Timer elapsed */
/* If key hit and timer, key hit takes precedence. */
{
{
/* for next loop around */
/* turn the calculator off until they turn it on */
/* signal they want to quit */
/* turn the calculator off until they turn it on */
/* regular key hit */
/* push the key back to key queue */
/* reset APD */
/* Break key */
/* go back to sleep */
/* waitOneMinForKey */
Not for Distribution
{
Beta Version January 26, 2001