- BugFix: restoring of temp2 register in ISR termination was incorrect
- added some code to T0ms to improve accurracy of millisecond timer.  Microseconds are now tracked so that timer only loses 1 sec for every hour.
- went back to using 976 Hz to reduce interrupt loading.
- exms now kept in ram since it gets read so often.  Reading from EEPROM was slowing execution down.