IBM microcomputers Programming 4 Microcomputers 2 Amateurs' manuals 1 C (Computer program language) 1 Computer input-output equipment 1 Design and construction 1 Equipment and supplies 1 IBM Personal System/2 (Computer system) 1 IBM compatible computers 1 IBM-compatible computers 1 Information display systems 1 Maintenance and repair 1 Repairing 1 Subroutines (Computer programs) 1 Upgrading 1