This packet of four learning modules on computers is one of 20 such packets developed for apprenticeship training for stationary engineers. Introductory materials are a complete listing of all available modules and a supplementary reference list. Each module contains some or all of these components: goal, performance indicators, objectives, directions, vocabulary, overview, information sheets, self tests, final test, task sheets, and answer keys. The four training modules cover digital language, digital logic, computer overview, and computer software. (YLB)