Although not officially multitasking, each task completes some work and then returns to the main loop to allow time for other tasks. Using the built-in timer, an interrupt occurs every thousandth of a second which scans a table to set alarms or immediately call registered routines. The microcontroller is running at 32 MHz internally, so many instructions complete in a single clock cycle. See PLL for schematics and source code. Power Bugdozer uses two 9-volt batteries, for a maximum of 18 volts.
Rechargeable batteries are cheaper per use and landfill friendlier.
The batteries are center tapped for the motherboard. So, only half the voltage is passed to the regulator, wasting less power. Full voltage is provided to the LEDs and DC motors. The Maxim MAX603 is at the heart of the onboard power supply. It can continue providing 5 volts even when the source drops to only 5.32 volts.