An Advanced Control and Display Module has been developed for an Underwater Portable Life Support System. The system architecture may be applicable for future EVA applications. The Module employs a Single Chip Microcontroller, an Electroluminescent Display, and an Operator Control Panel. The Module automatically controls the amount of oxygen in the diving mixture as a function of depth. Predive and postdive checkout, present diving status, and emergency procedures are all available through the display.