After having published my first book, Computer Networks: Architecture, Protocols, and Software, friends asked me how long it took to write the book. My reply was that on the surface it took about three years from beginning to end; below the surface it took more like thirty years. Yet, my job is not done unless I write a book on computer architecture and discuss some of the background Inaterials. Most first generation computer architects are physicists who learned everything about computers on the job. Second generation computer architects studied the basics in school and later practiced in industry. My academic training enabled me to read the design documents of IBM 360 Operating Systems in the 1970s. This painstaking effort broadened my horizons about real issues, and to this day I feel very much obliged.
In the 1990s, while I studied the blue book on the telecommunication network design by ITU-T (International Telecommunications Union - Telecommunication Standardization Sector), I was able to make suggestions for improving the design. As you may not know, in 1962 I came to this great country without a penny. My life has changed ever since my late friend Bob Chen convinced me to study computers. Back then we knew so little about computers and it took us three months to find out that a compiler is software, not hardware. Today, a compiler can be embedded in hardware. Technologies come and go, but theories remain. May this book bring you confidence and success.