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Forth: Write Your Own Interpreter, 1981 Article Kilobaud Micro Mag


Experienced Member
Sep 28, 2011
Michigan, USA
Hi, During the past year I built a TTL computer from scratch and now I am in the process of writing a custom programming language for it. My machine has dual hardware stacks: Return and Data. I was having a hard time understanding how Forth works 'under the hood'. I recently found a terrific vintage article in Kilobaud Microcomputing Magazine from February, 1981. The article was written by Richard Fritzson and does an outstanding job of describing how Forth really works. The title of the article is "Write Your Own FORTH Interpreter". I would highly recommend this article to anyone interested in Forth and how it works, especially if your enjoy writing such things on your own. The article starts on Page 76. I have posted a few photos here: The cover, and first 2 pages of the article. (FYI: The following month's issue also has a tutorial about writing a Forth compiler, by the same author) Thanks! Michael



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Experienced Member
Dec 6, 2011
Dallas, TX
It's a great article: clear, accessible, full of meaty content, and actionable. I remember reading it. That article got me fired up to write a version of the interpreter for my OSI. I was impressed by how rapidly it was possible to be working in a high-level language while staying within the editor/assembler.

There's also a really great article on FORTH implementation in the Sept. 1980 byte (Varieties for Threaded Code for Language Implementation, by Terry Ritter, p. 20). And of course the August 1980 Byte Language issue on FORTH put the language on the radar of many hobbyists.
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Veteran Member
Apr 23, 2020
At the time Kilobaud was my favorite computer magazine. Always enjoyed BYTE, but for whatever reason I liked the article selection of Kilobaud better.

Exploring the FORTH space is a real black hole. Endless varieties and implementations. Feel free to ask specific questions, lots of scattered FORTH knowledge about.