4 volatile u8 chime_count;
5 volatile u8 unchime_count; /* silence counter */
8 /* called from the RTI interrupt, sees if we need to turn the chime on or
9 * off (chime would be on for N RTI cycles)
13 --chime_count; /* interrupts masked here, so this won't result in badness */
16 if (unchime_count) --unchime_count;