Starting FORTH has been the classic Forth tutorial and textbook since its first release. Many experienced programmers have commented on its concise utility and completeness. Beginners will find a carefully planned introduction to the Forth programming language that will prepare them for other books like Forth Application Techniques and Forth Programmer’s Handbook.



FORTH, Inc. and the book’s author, Leo Brodie, thank the global community for its continued enthusiasm for this book. Many have sought a new copy, a used copy, or have asked for a reprinting. It is our pleasure to now present both a downloadable PDF of Starting FORTH (First Edition) as will as an updated online edition, with great appreciation for work done by Marcel Hendrix to generate the web version on which these pages were based.

“…I hope this book is not so easy and enjoyable that it seems trivial. Be warned that there is heavy content here and that you can learn much about computers and compilers as well as about programming.” —Charles Moore, Forth’s inventor

“A Forth to be reckoned with…” —Leo Brodie, Author

First edition (PDF)

This was the start of Starting Forth.

The book arrived at a time when personal computers still were striving to be taken seriously. The same was true of the Forth programming language, so the whimsical cartoons and illustrations Leo Brodie brought to his book caused concern in some quarters. Still, they made novel language concepts more palatable, helped level the learning curve, and dovetailed with the computer revolution’s subtext that if learning is a good thing, learning through play is better.

Leo’s art survived, and his book sold out more than once and went to subsequent editions. It is still available, now online, with code examples adapted to modern ANS/ISO Forth standards.

And the language itself? Forth is alive and well, and can be found at both .com and .org.

This PDF version is a scan of a clean copy of the first edition. It is searchable, and PDF bookmarks have been added to help navigate. This is a copyrighted work. You may download it for your own use. You may not post a copy of it anywhere without permission from FORTH, Inc.

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Online edition

Starting Forth, the Forth language tutorial, is shared freely here in its official online edition. Updates to the original text include code examples that run on iForth and SwiftForth systems. Aficionados (and detractors) of the original book’s illustrations will find most of them restored in this edition by FORTH, Inc.

Notes about this online edition

Changes made by FORTH, Inc. to Marcel’s version were primarily related to internet coding standards and visual presentation. We also restored the book’s original illustrations here, in most cases. The following notes are also relevant and important to those familiar with the original edition.

Notes by Marcel Hendrix

This transcript is not an exact reproduction. Forth code has been ANSified. All code should run on at least SwiftForth and iForth. Where necessary, statements that were valid in 1981 have been exchanged with statements more appropriate for 2003 (when this tribute was written).

I have assumed a 32-bit, byte-addressing Forth with 8-bit characters. The address returned by WORD is assumed to be HERE. This allows the common trick of ALLOTing length of str CHARS after using WORD in order to compile string str to memory. Multitasking issues are ignored (e.g. no >TYPE, just TYPE). Division is symmetric, not floored, and two’s complement is assumed throughout. SwiftForth and iForth work splendidly with it, but other Forths will work too. Chapter 7 exploits extended uses of number conversion. Most Forths are broken in this respect, but iForth and SwiftForth support these neat features.

Continue to online edition…