Duntenmann, Jeff. Inside the Power PC Revolution. Scottsdale, AZ: Coripolis Group Books, 1995. Good comparative descriptions of different architectures, particularly CISC vs. RISC.
Malone, Michael S. The Microprocessor: A Biography. Santa Clara: Telos, 1995. Excellent, both on the technology and on the industry.
Prasad, Nallur, and Savit, Jeffrey. IBM Mainframes: Architecture and Design. Second edition. New York: McGraw Hill, Inc., 1994. Highly readable; clear explanations of basic hardware and software concepts.
Rosch, Winn L. The Winn L.Rosch Hardware Bible. Fifth Edition. Indianapolis, IN: Que, 1999. The indispensable reference on microcomputer hardware. Very clearly written and mostly accessible to the non-technical reader. ...