This is the 2nd largest sub-project in the entire μnix project. The ATBIOS is an ATmega microcontroller running custom firmware (ie the software) that performs all bootup sequences, has a direct access to the video subsystem, controls the AMPS (AVR Multi-Processing System) /reset signal, has it's own external DataFlash (16Mbit) to store text responses and menu dialogs, and controls (that is, proxies requests to/from) the temperature controller, debug console (192x64 graphical LCD), and RTC (Real Time Clock). To perform its duties it requires a GPIO expander IC.