The MC100 is a microprocessor based clock and auxiliary circuit controller capable of synchronizing both digital and analog secondary clocks. The MC100 provides automatic corrections for power outages as well as programmed events such as daylight savings. Powered by a 120VAC supply, the MC100 utilizes a 10 year lithium battery for backup during power outages. A user-selectable time base allows the master clock to either monitor the power-line frequency, internal crystal oscillator as well as an optional GPS or LAN interface to provide the most accurate time keeping. The MC100 comes standard with four circuits which may be used as either clock circuits or auxiliary circuits for tones, bells, and other timed events. Each circuit has an indicating LED and an OFF/AUTO/RESET slide switch for ease of manual control. The wall mount MC100 may be expanded to up to 12 circuits with the addition of EXP-4 circuit expander boards. Programming is easy utilizing a backlit 32 character liquid crystal display and a 16 button keypad. The multifunction keypad provides single button menu access allowing quick and easy time, schedule, and setup changes. Two level password security may be used to protect technician level settings and programmed events. The MC100 supports three program schedules with up to 200 program entries. Each event duration is programmable from 1 second to over 4 days. Attractive neutral Powder Gray finish with Night Blue graphic overlay complete with label pockets for custom circuit legends.