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"Understanding the Apple II", a Review.....Bob Sander-Cederlof

If you want the real inside scoop on the Apple II, you need "Understanding the Apple II".  Following close on the heels of Gayler's "Apple II Circuit Description", this book is no second-place sequel.

"Understanding..." was written by Jim Sather, a former ITT technical representative, after many moons of trial-and-error, pick-and-shovel research into the inner sanctum of our favorite computer.  Jim has a gift for clearly explaining how things work.  My degree is a little rusty, or mildewed, or whatever, and hardware never was my long suit.  But Jim makes it all make sense for me.

The process of "understanding" starts with a few full color diagrams and charts.  In the back of the book there are two foldout full color charts of bus structure and chip layout.  Surprisingly, you find color sprinkled throughout the book, along with many black & white illustrations, photos, tables, diagrams, etc.

Sather describes microcomputer fundamentals with specific applications to the Apple II.  He carefully documents all the circuits on the motherboard, as well as the firmware and language cards, and Wozniak's patented disk controller.

The chapter on the disk drive and controller is especially thorough, devoting some 45 large pages, including many diagrams, to the exact workings of these devices.  I have never seen a better explication of the Apple's unique disk controller.

There are especially useful discussions of address decoding, RAM/ROM addressing, and bus structure.  Sather's readable style avoids much of the reference-book prose common to authoritative technical books.

Each chapter ends with some of nearly two dozen hardware & software projects, including reprogramming screen character sets, an NMI based single stepper, detecting and using television sync, modifying the firmware card so the F8 ROM can be switch-selected, and more.

"Understanding..." begins with a foreword by Steve Wozniak, and ends near an appendix describing a conversation with Woz about some of the original design decisions that made our Apples what they are today.

This would be a good text book in computer hardware fundamentals at high school level or above.  Most of the courses I took in college (now over 25 years ago!) were rather abstract and difficult to relate to real applications.  What better way to understand how computers work, how they can be modified and maintained, and how to design them, than to dissect a living breathing example like the Apple II!
!np
Here's a quick look at the structure of  "Understanding the Apple II":

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Chapters
  1 Overview
  2 Bus Structure
  3 Timing Generation and the Video Scanner
  4 The 6502 Microprocessor
  5 RAM
  6 ROM
  7 Address Decoding and I/O
  8 Video Generation
  9 Disk Controller
 10 Maintenance and Care

Glossary of 7 pages, about 150 entries.

Appendices:  references, trademarks, 6502 data sheets, program listings, logic circuits primer, number systems primer, apple ii revisional info, historical notes, conversation with Woz, how to remove the motherboard, list of figures and tables.

Schematics

Index
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"Understanding the Apple II" describes the Apple II and Apple II Plus.  Much of the book's information, especially the chapter on the disk controller, applies also to the Apple //e.  "Understanding the Apple //e" is promised sometime in 1984.

Understanding the Apple II, Jim Sather.  About 356 pages.  Quality Software, $22.95 (Buy it from us for only $21 + shipping).
