This text is the concepts portion of the O'Leary "Microcomputing Annual Edition" containing 300 pages of computer concepts. It remains up-to-date with the dynamic and ever changing world of microcomputer concepts and there is coverage of: systems software changes in MS-DOS 5.0, DR DOS 6.0, Windows 3.1, and OS/2; powerful supercomputers; conventional, extended, expanded and cache memory; pen-based computing; data compression; magneto-optical disk drives; faster modes; and visual BASIC. The "Look at the future" sections have been updated to include NT operating systems; taligent; object-oriented programming; holographic storage; light-sensitive bacteria protein for storage; and videophones. There are also new discussion questions and projects - 2 per chapter, and a new appendix entitled "Purchasing your own PC".