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What was the TRS-80's contribution to personal computing?

   “ We primed the pump. ”

      - Steve Leininger,
who built the first TRS-80

book back cover


“The book is full of memorable details and names... . For those of us who got hooked on the software thing at an impressionable age, this is exciting stuff. And Theresa is a fine writer. The story moves along briskly ...there's an innocence and earnestness and honesty in the book that makes you willing to let them tell their story in their way. ”    Michael Swaine, Swaine's Flames, Dr. Dobbs Journal, August 2007    Read Swaine's column

“As one of the co-creators, I know the history of the TRS-80. This is the most accurate history of this 'Industry Creating Machine' out there. ”   
Don French, who, with Steve Leininger, designed the TRS-80  (review at

“Theresa, the book came and it's great! I learned things about the TRS80 that I had never guessed...”   Bruce Damer, DigiBarn Computer Museum

“I LIKE it! I think many others will, too. Thank you for preserving so much information on this watershed product in so many lives. ”   Dick and Jill Miller, Miller Microcomputer Services

“ ...I am thoroughly enjoying it! The book fills in so many of the gaps of the history of the machine for me. I lived it but did not know all the things going on at the time. ”   Scott Adams, creator of the Adventure games

From the Bleeding Edge of Computer History

  • True stories, based on interviews with microcomputer pioneers like Steve Leininger, Don French, Randy Cook, Vern Hester and others
  • The personal stories of David and Theresa Welsh, whose software products were sold worldwide
  • The games, the magazines, the scams, and even the robots that were supposed to be in every home by the year 2000
  • 355 pages including an Index
  • Photos and illustrations of early ads and products

121 illustrations!

   The True Story of Microcomputer Pioneers

Radio Shack's TRS-80 Launched a Revolution in 1977

Priming the Pump: How TRS-80 Enthusiasts Helped Spark the PC Revolution reveals
the hidden history of personal computing.

The authors witnessed the birth of the computer revolution as part of the community of small software entrepreneurs who created the first applications for personal computers. They personally knew many of the principle players whose accomplishments are the stuff of legends. This book is the ONLY BOOK to capture this unique era, the late 1970s and early 1980s, when personal computing was just an idea -- an idea whose time had come!

In these pages you will learn how a young engineer named Steve Leininger, working alone, built the first TRS-80. Development costs were less than $150,000. Leininger had to make a product that could be sold for a price Radio Shack customers could afford. Yet no one had ever sold a complete off-the-shelf personal computer before.

The TRS-80 was not the first microcomputer. First were the homebuilt models and the kits, starting with the Altair in 1975. You couldn't buy an Altair in a store; it was only available through mail order, and when your kit arrived, you had to put it together yourself. There was no software, so you programmed it yourself by toggling switches on the front panel.

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 ...the most accurate history of this "Industry Creating Machine" out there.

  Don French, co-creator of the TRS-80

Other kit computers followed, but none were taken seriously. That changed because of one fateful day when a computer hobbyist at Tandy Corporation (parent of Radio Shack), Don French, suggested to his bosses that they should build and sell a real computer. The Tandy managers weren't sure about this idea, but they decided to investigate and paid a visit to Silicon Valley. There they met and made an offer to Steve Leininger, who siezed an opportunity to do hands-on work with something he loved: the new microchips that hobbyists were using to build their own computers.

Carried along by his own enthusiasm for the project, Leininger had few people to assist him; he was doing something no one had ever done before. The result of his efforts was the revolutionary TRS-80 Model I, a product so successful it overwhelmingly exceeded even its most optimistic sales predictions.

The first off-the-shelf microcomputer.

This is the Model I, as introduced on August 3, 1977 in New York City for a price of $599.95 The tape player was the storage device. There was no hard drive and only 4K of memory. You programmed it with a tiny BASIC built into the machine or with Z80 assembly language.

The Real Story, From the People Who Lived It

Individual programmers, not giant corporations, created the software business. Before Microsoft was a household word, most business programs and games were created by one person, not, as in later years, by teams of Computer Science graduates. One person, eagerly soaking up information from programming manuals and magazine articles, was capable of creating software... using a computer with a mere 16K of memory and no hard drive. Responding to the lack of software, microcomputer programmers found they could start selling their creations to buyers clamoring for applications.

Of course, software already existed. It ran on the expensive IBM mainframes used by Big Business. Left out of this scenario were small businesses, which could not afford computers, and individuals, who had no chance to use or program a computer. But in the late 1970s a revolution began. The personal computer revolution. Those first machines, meant for individuals, were called microcomputers.

Introduction of the TRS-80 meant, for the first time, anyone could experiment with software and affordably use word processing, spreadsheets, accounting, database and other kinds of software... as soon as someone wrote programs to perform those functions and made them available. And lots of individuals working in basements and garages did create those programs. Most of them had never done any programming before. By the early 1980s, customers could choose from over 30 word processors.

David Welsh, shown above with the TRS-80 Model III, was one of those self-taught programmers. His word processor, Lazy Writer, was sold worldwide and had many enthusiastic fans who were eager to throw away their typewriters.


Steve Leininger, hired away from Silicon Valley by Tandy Corp., worked alone amid the grimy surroundings of an old Fort Worth saddle factory and built the prototype TRS-80; the final development cost was less than $150,000.

John Roach, Tandy's product manager, got an agreement from Charles Tandy to build 3500 units after Leininger demonstrated the prototype; this was exactly the number of stores they had -- Roach figured if no one bought the computers, at least the stores could use them. Don French, a true believer, predicted they'd sell 50,000 the first year and urged the company to gear up the factory for mass production. Tandy managers, thinking they could never sell that many, were surprised when, in the weeks after the introduction, the Tandy switchboard was paralyzed with over 15,000 calls from people wanting to order a TRS-80. In the first year, over 250,000 people went on waiting lists to buy a TRS-80!

Tandy contracted with Randy Cook to create a Disk Operating System (TRSDOS) for its next generation TRS-80, which would come with floppy disk drives. The company agreed Cook would retain ownership of the code. But Cook, believing Tandy violated the agreement, created a rival DOS which he sold through his own company. Clueless Tandy managers found Cooks' name embedded in the TRSDOS code.

TRSDOS replacements appeared - five of them - and programmers made up their own homespun magazine ads touting their products great features and attacking their rivals' products in the pages of magazines like 80 Micro, the most popular of many publications devoted to the TRS-80.

Wayne Green, publisher of popular computer magazines, promised to "editorially break" Radio Shack because they would not carry his 80 Micro magazine in their stores; his vitriolic column often lambasted Radio Shack CEO John Roach.

Bill Schroeder, a successful businessman, bankrolled Logical Systems, Inc. and sold Tandy on LDOS as the company-sponsored TRSDOS replacement. A state-of-the-art headquarters and a pile of money followed the lucrative contract, but once he sensed the coming demise of the TRS-80, Schroeder simply shut down his company, a move he came to regret.

Scott Adams created popular Adventure games for the TRS-80 and other early microcomputers, became a celebrity in the magazines, but went broke when he produced too many game cartridges for a computer that died in the marketplace.

Along with microcomputers, robots were hot. Meet the robots of the 1980s - and the man who said we were all going to have mechanical men in our homes by the year 2000. A magazine boldly declared it "The Robotics Age," but this revolution never achieved its promise.

A notorious scam artist preyed on the gullibility of microcomputer enthusiasts, destroying the Southern California Computer Society with a Ponzi scheme, then bilking TRS-80 owners out of thousands of dollars with magazine ads from a bogus company called World Power Systems showing phony products.

Here is the real story of personal computing, based on interviews with pioneers who created the hardware and software that spawned a revolution. They tell their story for the first time, captured by the authors, who lived through it all. Despite the persistent claim that Apple or IBM invented personal computing, it's just not so. This book tells the story that has not been told before, and your tour guides are David and Theresa Welsh, whose insights are a valuable resource to understanding the technological and cultural revolution represented by personal computing.


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The eBook version includes color illustrations (although many of the 122 illustrations are black and white because that is their original color). Don't have an eReader? You can read Priming the Pump (with color) by downloading a free copy of Kindle for PC from or go to and download the free Nook for PC app or download Adobe Digital Editions, a free reader from Or read it on your iPad or any device that uses the Kindle or epub format.

NEW and Absolutely Free! Illustrated Slide Show (40 colorful slides) on the TRS-80 era, incorporating material from Priming the Pump. Show it at your next meeting; enjoy it on your PC or iPad.

Download Slide Show in PDF format (size: 17.4MB)

More Retro Computing

Remember PacMan? Q*bert?

Click here to see fabulous cartoons as DetRiotGirl interviews video game stars of yesteryear

PS: DetRiotGirl is our talented daughter,
   Amy Welsh

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