Clock- The Clock layer provides a real-time clock with a battery backup that keeps current time and date information as needed for timing-critical applications. [details...]

PCMCIA- The PCMCIA layer is a general utility layer for interfacing with available PCMCIA devices commonly used with laptop and handheld computers . [details...]

Power- The Power layer is used to add additional power to the secondary power bus on the Tower. Power can be added either from batteries, or from a regulated transformer jack. [details...]