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FORTH day is today. Special guest Chuck Moore


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SVFIG hosts FORTH day annually. It is today, Sat, Nov 21.   Here is the link and agenda.

All times are PST (Palo Alto, CA)




900 --- Welcome --- Program Chairman Kevin Appert (5 minutes)


0905 --- EForth implemented in C --- Brad Nelson (20 minutes)

An exploration of various approaches to build EForth on top of C, we'll look at variations on the core interpreter, how to populate the dictionary, X-Macros, alternate memory models, and will draw comparisons with approaches taken in cforth and gForth.

0925 --- Hacking Farmer's Markets --- Mitch Bradley (20 minutes)
"By frequenting local Farmer's Markets and talking to the vendors, I have discovered a lot of need for small-scale automation. I'll show a collection of gadgets made from low-cost microprocessors, motors, sensors, and hardware store parts, with simple programming in Forth, that are a great help to small farmers and food producers."
0945 --- AIBot Board Update --- Don Golding (5 minutes)


0950 --- Visions of Future Forth --- Don Golding (10 minutes)

Forth has been used in both AI and space for many decades,  Forth's architecture fits perfectly for use in future space systems with low bandwidth communications links.  Incremental compilation, interpretive, extensible without a complete re-compile, can be used as a powerful terminal program for deep space robots,  You don't need to reflash the microprocessor with a large binary image over a low rate link.

1000 --- Matrices In Forth --- Bill Ragsdale (20Minutes)
"I'm not sure if this has been covered over the years. The key idea is from Julian Noble's book Scientific Forth. I've got basic matrix support in 80 lines of code with lots of white space. (create, fill, list, transpose.) I can be time adjusted to your need."

1020 --- A Slightly Different Forth Compiler Design --- Joseph O'Connor
(20 Minutes)
The Creole Forth compiler has several unusual features which include the lack of a STATE variable. This presentation will discuss its design features and their advantages.

1040 --- Forth Challenge ... show off your solution! --- Bill Ragsdale
(duration will depend on number of presenters - reserve your spot now!)
<<Create a translator from decimal into Roman numerals from 1 to 1001. A typical demonstration would be to print: 1 to 20 and 990 to 1001. You may choose either format for numbers such as 4: IV or IIII. Note the Romans often intermixed the formats as the Colosseum uses both. See Excel's roman() function.

As a historical note, this was presented on a handout by the Forth Interest Group in their exhibit at the third West Coast Computer Faire in 1978. >>>
1130 --- Forth Trivia Contest --- MC Bill Ragsdale (may run through lunch)
A trivia contest in the form of Jeopardy, really. (With the green category board and all!)
1200 noon --- Virtual lunch, chat, intros, networking
1230 --- Fireside Chat --- Chuck
1300 --- GreenArrays Update
1330 --- Programming GA144 using GA144 only --- Daniel Kalny (45 minutes)
"Chuck Moore began porting colorForth to GA144 in 2010. The project remained unfinished until 2017, when Chuck gave me his source code. Through several design iterations I finally arrived at a standalone development system for GA chips, running on a single GA144 only. In my talk I will present etherforth in its current version, and with the help of a few simple demo applications I'll show how the system works, and what kind of projects it can be used for."


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Here are some of my notes from the last part of FORTH day.


Charles H. Moore, inventor of FORTH.

Chuck Moore gave a "fireside chat". He showed us around his everyday FORTH blocks such as his dashboard, various clocks, astronomy he wants to memorize, and short quotes that give him fresh ideas.


Q. Could FORTH be a mainstream language like C or Java?
A. I don't think it needs to become a mainstream language.

   FORTH is a language to solve well-defined problems.
   It is a very good niche language. It is a very good tool. 
   FORTH requires the imagination, effort, and skill of a programmer.

   Always, FORTH can be used by people like us, without the world giving us permission.

Greg Bailey and Daniel Kalny of GreenArrays


  • GreenArrays GA144 is a chip with 144 CPU nodes for running FORTH.
  • Designed by Chuck Moore.
  • It is not a massively parallel CPU. Each CPU is given a specific, small task.
  • There is no system-wide clock. Clock distribution wastes a lot of energy. Each transition of the clock costs Vdd*C.
  • When a CPU has nothing to do, it goes to sleep. Transitions take picoseconds. 
  • Message passing by Ether lets CPUs send executable code+data to any other.
  • Eval board has a host GA144 with complete user interface, and a target GA144.
  • Pictures of how nodes are allocated to run the host software. For instance, one or more nodes for:
    •    keyboard, vga interface, GA144 programmer, at the edges of the chip.
    •    Lexical parser, number parser, word lookup, dictionary nodes.
  • Best for low-power, intermittent embedded systems. For example: bridge monitoring, lasting 20 years.
  • GA144 itself is designed in OKAD, in ColorFORTH. OKAD creates transistor layout by running a FORTH program.
  • GLOW is also a FORTH for placing transistors and poly lines. Working to re-generate the GA144 in GLOW.
  • FORTH is ideal for building up low-level components such as gates, modules, CPUs, and repeating them.
  • SystemVerilog is bad at power efficiency, OKAD/GLOW is unbeatable. 














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  • 11 months later...
  • 3 weeks later...

So far today:


Xuyang Chen.  MovForth is a Forth compiler on top of LLVM. It compiles down to very optimized assembly.
Intended to package an application and go fast. You can still have a regular Forth compiler at run-time, but your code is not in a dictionary.

C.H. Ting.   Forth implemented in Javascript. Can build sophisticated web pages using Forth. Forth613.html shows an interactive Forth shell. 

Brad Nelson.  CSG in Forth. Build up your model geometry from primitives. Code takes slices of your model, and writes G-code to control a 3D printer. Nice interactive process of tweaking model. 

Bill Ragsdale.    Effective presentations on Zoom. SAFW and other structures, talk beginning, middle, end. Keep code to a snippet and make it big font. People will read slide text first, missing your talk, so keep bullet points short, or pause. Simplify your background and light your face with no shadows (tissue paper ring light). Use 2 cameras and show your project. Now you know what features to exploit in Zoom talks.

Dennis Ruffer.  Zephyr is a small OS that runs on 100s of boards, and also on any POSIX (Linux command line!) Employers  Intends to do some Forth on top of it. Ficl is a Forth-inspired command language for interactive board bring-up. (What *I* want to use CamelForth for on Geneve2020)   ficl is a dev tool - in a delivered product everything is known at compile time. 


Dave Jaffe:  SVFIG videos can be found at http://forth.org/svfig/videos/index.html
Thanks to Brad Nelson for recording and segmenting the Zoom video.


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  • 1 year later...

Copying here from https://www.meetup.com/SV-FIG/events/296503788/


New Zoom room - seems there is no password this year. 

Chuck Moore at 1:57 Pacific time, PTC-0800


SVFIG Forth Day In Person and Zoom --- Third Saturday!



go to: http://forth.org/zoom/
for 2023 SVFIG Forth Day Zoom Meeting
**The Zoom Room is open 24-7, stop by and give it a try!


There will be an IN-PERSON meeting at Stanford! Details below.


*** PLEASE NOTE 09:00 AM (Pacific Daylight Savings) START TIME
***All durations and descriptions are approximate or perhaps entirely inconsistent with what will eventually transpire.

AGENDA (descriptions edited to fit MeetUp 5000 character limit)

09:00 --- WELCOME --- Kevin Appert, Program Chairman and Master of Ceremonies
This will incorporate the ceremonial starting of the Zoom recorder.

09:05 --- The J1 Family of Soft core Processors --- Christopher Lozinski
“My last SVFIG talk, “Review of Soft Core Forth Processors”, was a high level market overview.
I am now busy hacking the Mecrisp-Ice source code. This talk explains why I chose to build on
that code base. “

09:35 --- ISO Weeks Programming Challenge --- Bill Ragsdale
“The ISO 8601 Standard week is used for planning business finance and operations. A key element is numbering the weeks of the year, albeit with a non-intuitive method.

10:05 --- Lambdas in Forth --- Brad Nelson
“Lambda expressions have become a popular language feature, finding their way into Python, Java, and even C++.

10:35 --- Photo Op and Bathroom Break

10:40 --- System Forth --- Samuel Falvo II
"A quick overview...
--- I have solved the wordlist bug in my System Forth implementation, so wordlists actually work!!
--- I also implemented LIST, so I can see what the heck I'm about to load now.
:D And PAGE and AT-XY too.
---Tic-tac-toe game demo."

11:00 --- FluidNC DIY CNC --- Mitch Bradley
FluidNC is CNC controller firmware that runs on very low cost hardware, but is flexible enough to support many different kinds of complex machines. I will introduce the basics of CNC controllers, explain how FluidNC came about, and discuss the challenges of supporting an open source project of this magnitude in the context of a DIY community.

11:20 --- Forth Recognizers in SwiftForth --- Leon Wagner - President - FORTH, Inc.
The Forth interpreter doesn’t have a standard method for extending how it processes various kinds of text tokens. There’s a white paper here on our website:

11:40 --- Fall Haikus --- Brad Nelson
Using the power of Forth Haikus we'll create seasonal fall images and animations to celebrate Forth Day.

11:50 --- Lunch

12:32 --- CORE I Project Update and AI IS the Forth's "Killer APP" --- Don Golding

12:52 --- 2023 State of the CoSy Report --- Bob Armstrong
“CoSy Status Report? (Can't think of anything succinct to add)
CoSy , Yesterday , Today and Tomorrow? (honors Sophia Loren , but I don't want to spend time on Yesterday)
2023 State of the CoSy Report has an official sound to it . Whatever.”

13:12 --- Getting Started with arrayForth --- Greg Bailey <greg@greenarraychips.com>
“My plan would be to deliver on my promise a year ago to present a video on
the simple process of downloading, installing and using arrayForth 3”

13:57 --- Fireside Chat --- Chuck Moore
It's a Forth Day tradition!

15:00 --- Adjourn
The recording will be stopped without ceremony. Good fellowship and conversation can continue in our tastefully furnished Zoom Room.

Message Kevin Appert for more info! Send messages through Meetup-message, email, etc.

Zoom meetings are recorded and presented on our YouTube channel:







SVFIG will meet in the Peterson Building (Building 550) on the campus of Stanford University.

Parking: There is open parking on weekends. You may park in any A or C designated areas or metered space. There is no need to feed the meter on the weekends. Do not park in any place marked with 24/7 restrictions! Read the signs!

Building Entrance: Make your way to the Panama Mall entrance of the Peterson Building. The door is labeled Building 550 - Mechanical Engineering Design Group. Do not ask Stanford students to let you in and do not enter the building behind them.

Here is the googlie map showing Peterson:

I recommend parking in the lot at the corner of Santa Teresa and Lomita:

For maps and parking info, go here: (ignore the old dates)


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