DIYers, Digitial Computers, and today’s musings

Understanding Digital Computers

 I snapped a picture of this Amazon page this morning. Is this real? The owner of a copy of Forrest’s paper back has a $55 asking price and he’s rejected four offers and holding fast to the asking price? 

When I read this book, I thought it was a lot like a Popeye experience.. remember, he eats his spinach, and look out!  This book is a little like pouring knowledge out of a can into your head. 

So Forrest, if you stumble onto this page, maybe you buy the rights of this book back from Radio Shack, or make it available in E book, or talk to them at least.

So many of the books I read long ago seem obsolete today, but there are treasures that would be part of a computer science course if I were designing it, and Forrest’s book would be one of  them.  Of course you know I’d be curious enough to ask questions of perspective students and I’d think there were things to learn.  Have you ever pulled a spark plug from a lawn mower or small engine? What color was the plug? Do you like to chop wood?  When you open a faucet, which way do you turn it?

I’d ask a series of questions only because I’m convinced curious people can’t help but do these things and note the results, (unless they are deprived of opportunities being warehoused in the inner city).  And, I’d want to conduct my own little experiment… how did the students answer the questions, and which students did best in the class? You might remember an experience I had years ago, and talked about… eating lunch with a famous guy who made up a series of questions from which he selected candidates to be military pilots in WWII. No, it wasn’t like he called up and invited me to lunch, I was part of a study he was paid to conduct. You normally remember being a rat in a maze, I close my eyes today and remember the room, where I sat, and where he sat at the table. I was careful not to eat like a horse, and grateful they didn’t serve BBQed Ribs. His accounts were so interesting, it was hard to eat at all.   

There’s little doubt in my mind that our Tuskegee Airmen were screened by the same test as white Airmen, and they picked the cream of the crop.  But what I’m curious about is the ratio of those who grew up in the inner city, and those who lived in the country? Are inner city kids denied experiences that are building blocks, and does this inner city upbringing handicap you in measurable ways? 

We get back to that test…the Good Doctor phrased his question “do you like to chop wood?” What amazed him was almost every pilot that did well said he liked to chop wood! And the feed back from instructors in flight school lead to the conclusion that if you answered that one question as a “no”, you were well on your way to being de-selected for flight school.  I’ll let you analyze the why…

I’ve written many times about hands on versus book learning, and I was thinking… there are times when the information in a book paints a much clearer picture of what’s going on.  Even if you pop the top off and stare inside a digital chip, there’s not much to see or learn..  

Fact is, back in the late seventies I knew a few guys that did that as part of their job,  using an electron microscope to read the contents of a masked rom… often from their competition…  It would have been far easier and quicker to read the memory contents on a page along with the remarks.. if only they could..   

One of the most poetic drawings I remember was a detached drawing of a relay logic circuit used to check parity of an originating number in a relay logic telephone switch. Since it could be part of a billing record, they really wanted to get it right, and looking at the drawing was an experience similar to hearing a favorite musical score, it was elegant, it was a form of beauty, but staring at the equipment bay you saw tubes, coils, mercury filled reed relays, cool… but not poetic.

Here’s a page  I found today, and on it is a mention of Forrest Mims, one of my heros.  This page gives him credit for the PIP, and Forrest’s presentation of how the PIP works is like a musical score.  What you walk away with is a vivid picture of how a computer works, you can literally memorize all the op codes, and see the processor working in your head as you read.  The book can NOT be found on line today, the title “Understanding Digital Computers”.

Forrest.. does this mean the book will be copied overseas and made for sale?

Years and years after reading Forrest’s book I told Forrest it was like a secret weapon, I went on to tell him that anyone reading his book right before taking a certain test in Telco would pass! It allowed a few clerical people I knew to move from clerical positions being phased out to good paying entry-level tech jobs. I bought a few of Forrest’s books for people and told a lot of other people to buy them..  

You know what’s coming don’t you? Forrest said.. “George.. I was writing that book as I was doing it.”   the pages Forrest wrote were minutes behind the bread board work, and loading the addresses and executing the contents. Hands on!  (Hands on DIY!) and don’t we know near magic things happen when you put your hands on it..     

If you remember the first time you saw a reduction gear box with one gear in it?

and stuttered “wow!”.

That little book of Forrest’s  is like a spring-board, it may have been written in 1978, but it’s as valid today as it ever was, and he has written a lot of good books on Electrical Devices, it all helps to develop critical thought  in machines and their designs, and it translates over to other things once you see how similar they are.  

Thanks Forrest, thanks Radio Shack..  and Heathkit too 🙂 

http://en.wikipedia.org/wiki/Forrest_Mims

  GB