This self-study course is designed to familiarize Marine Corps enlisted personnel with the principles of solid-state devices and their functions. The course contains four study units. Each study unit begins with a general objective, which is a statement of what the student should learn from the unit. The study units are divided into numbered work units, each presenting one or more specific objectives. Text is furnished, illustrated as needed, for each work unit. At the end of the work units are study questions, with answers listed at the end of the study unit. A review lesson completes the course. The four units of the course cover the following subjects: semiconductor diodes; transistors; special devices; and solid-state power supplies. (KC)