previous | contents | next

14 Part 1 The structure of computers

notations must become formal programming languages, so that analysis and synthesis procedures can be carried on automatically in their terms. As we have noted, the development of ISP and PMS germinated from purely notational issues. We have not let our aspirations to turn them into simulation languages delay our use of them for purely descriptive purposes. Thus we accept the obligation also to develop them as operational tools. That is also an aspiration and cannot be dealt with anywhere within this book.

Plan of the book

We now have enough background to explain the structure of the book. Two other chapters complete the introductory part. Chapter 2 provides an exposition of the PMS and ISP descriptive systems. As we have just noted, this does not attempt to explore seriously the view of digital processing implicit in these notations, although it does provide a small amount of motivation. A summary of the language conventions and parameter values is given at the end of the book in the appendix.

Chapter 3 provides a description of the space of computer systems. One can view all computer systems as occupying a space whose dimensions are the various important systems features. Many features of the actual systems are relatively locked together. For example, word size and number of instructions in the repertoire covary; no 12-bit machine has 200 instructions but several with over 32 bits do. Thus the number of significant dimensions of variation is much less than the total number of features of computer systems. Such a space provides a basic frame in which to choose representative computer systems for inclusion in the book. We hope Chap. 3 will also justify our feeling that there is a diversity and proliferation of computer systems that is worthy of serious study.

The remainder of the book is divided into five parts (2 to 6, with the introduction constituting Part 1), and each part into sections. Each chapter gives a description of a computer system that is an instance of the part and section. Usually a chapter describes only one computer or computer system, although there are a few exceptions in Part 6 on computer families.

A word needs to be said about the "Virtual" Table of Contents. Many of the example computers are relevant to more than one part and section. Physically, they have to be located at one place. But we have permited multiple entries in the Contents, so that, for instance, Chap. 33 on the IBM 1800 appears in Sec. 1 of Part 2 as an example of a one-address ISP, in Sec. 1 of Part 4 as a terminal control, and finally in Sec. 2 of Part 5 as an example of a PMS with one central processor and multiple input/output processors (1 Pc, multi-Pio); physically it is located in the latter section. By using different type faces we hope the reader will not become confused between virtual and actual.

There is little point in outlining the content of the various parts and sections here. This is better done at the end of Chap. 3 after the computer space has been laid out.

References

Brackets are used to enclose author(s) and year of publication, e.g., [Darringer, 1969] or [Falkoff, Iverson, and Sussenguth, 1964]. A list of all the references in a chapter is given in code at the end of the chapter. The code refers to the bibliography at the end of the book. This 7- or 8-character code is as follows:

Characters 1:4 First four characters of the last name of author (or first author)
Character 5 First initial of author (or first author)
Characters 6:7 Year of publication- 1900
Character 8 (Optional) a, b, c used to denote multiple referenced publications of author in a year.

References

DarrJ69; FalkA64; HaneF68; RoseS67; SteeT6l; ZadeL63.

previous | contents | next