What is Forth?
Forth was created by Charles (“Chuck”) Moore in 1968, to control radio telescopes. When he wrote Forth, Charles Moore envisioned that the “fourth” generation of computers would be distributed controllers, in essence embedded systems (although that term had not yet been invented). Hence, he called his programming language “Fourth.” However, since the IBM 1130 that he used for development only allowed for five-character file names, the programming language became known simply as Forth.
Forth is unlike any other conventional programming language. Forth is an extensible, highly-interactive, stack-based language. It is extremely efficient and extremely versatile. The functionality of the language makes it ideal for debugging both system hardware and software.
Forth is commonly used in systems under development and is often retained by manufacturers in their computers. Forth was the first resident software on the then new Intel 8086 chip in 1978, and MacFORTH was the first resident development system for the Apple Macintosh in 1984. NASA’s Voyager spacecraft run Forth, providing for both efficient firmware and the ability to interactively debug across the vastness of space, and Forth was also used by NASA in the Space Shuttle's Star Tracker subsystem.
Forth is typically coded directly in assembly language both for speed of operation and to take advantage of the characteristics of the embedded computer.
Forth is unlike any other conventional programming language. Forth is an extensible, highly-interactive, stack-based language. It is extremely efficient and extremely versatile. The functionality of the language makes it ideal for debugging both system hardware and software.
Forth is commonly used in systems under development and is often retained by manufacturers in their computers. Forth was the first resident software on the then new Intel 8086 chip in 1978, and MacFORTH was the first resident development system for the Apple Macintosh in 1984. NASA’s Voyager spacecraft run Forth, providing for both efficient firmware and the ability to interactively debug across the vastness of space, and Forth was also used by NASA in the Space Shuttle's Star Tracker subsystem.
Forth is typically coded directly in assembly language both for speed of operation and to take advantage of the characteristics of the embedded computer.
Charles Moore has said that his concept for Forth is that each implementation of the language should be optimised to take advantage of the machine on which it is running, even if this optimization compromises the portability of the language. This philosophy is a major departure from conventional programming ideology. With Forth, speed and robustness are the goals, not the ability to port applications between platforms. One version of Forth can be quite different to another.
The Forth running on your Udamonic computer is FlashForth, written by Mikael Nordman for the PIC and AVR processors. The website for FlashForth is http://flashforth.com where you can find the original source code for version 5.0, as well as documentation. FlashForth is free and open source, released under GPL. FlashForth was modified to run on the Udamonic computers, and has additional support specific to the Udamonic hardware. The source code for standard FlashForth may be found on our Resources page. You can use the about command on your Udamonic computer to display version number and copyright information.
Forth is at once a compiler, an interpreter, a debugger and, in a fashion, an operating system too. Languages typically fall into one of two categories, they either compile to machine code for their target computer (C and C++), or they generate bytecodes to be interpreted by a virtual machine (Java and Python). Generally, interpreted languages are interactive (to varying degrees), while compiled languages are typically not interactive at all. Forth is also a compiled language, but it is a compiled language with a difference. It is interactive, yet runs with an efficiency not far removed from hand-written machine code. Commands (known as words in Forth) get an immediate response. This, coupled with Forth’s ability to talk directly to hardware, makes it an excellent environment for embedded system applications.
Forth is at once a compiler, an interpreter, a debugger and, in a fashion, an operating system too. Languages typically fall into one of two categories, they either compile to machine code for their target computer (C and C++), or they generate bytecodes to be interpreted by a virtual machine (Java and Python). Generally, interpreted languages are interactive (to varying degrees), while compiled languages are typically not interactive at all. Forth is also a compiled language, but it is a compiled language with a difference. It is interactive, yet runs with an efficiency not far removed from hand-written machine code. Commands (known as words in Forth) get an immediate response. This, coupled with Forth’s ability to talk directly to hardware, makes it an excellent environment for embedded system applications.
Forth words are the equivalent of functions in C, Python or Java, or subroutines in assembly language. Forth allows the execution of any word in isolation from the command line. Thus, words can be independently tested and verified outside of the main application. So rather than writing a single, large program, small segments of code are written and tested independently. These words are then combined to create new words, eventually ending up with a single word that is the whole application. This new word is also available to the developer, and in this way the language both grows and becomes richer as the developer works with it. In addition, the words used to create the new word are still available and can be run as programs in their own right, or used to create other new words. Forth is both versatile and powerful.
This form of program construction makes Forth a “bottom-up” language rather than the conventional “top-down” programming methodology. Words written to interact with specific aspects of hardware (at the initial debugging stage) may be later incorporated in higher-level diagnostics or in the final application itself.
This form of program construction makes Forth a “bottom-up” language rather than the conventional “top-down” programming methodology. Words written to interact with specific aspects of hardware (at the initial debugging stage) may be later incorporated in higher-level diagnostics or in the final application itself.
Advantages of Forth
Embedded systems development is a realm where efficiency, precision, and resource optimization reign supreme.
The Elegance of Simplicity
Forth's unique approach to programming is rooted in its simplicity. It's a stack-based, postfix notation language, which may sound unconventional at first, but it's precisely this simplicity that makes it exceptionally powerful for embedded systems. In the world of constrained resources, every byte of memory and every CPU cycle count. Forth's minimalistic syntax and small runtime footprint ensure that you can do more with less.
Efficient Resource Utilization
Embedded systems often have limited resources, making memory and processing power scarce commodities. Forth's lightweight nature and minimalistic syntax allow you to make the most of these precious resources. It excels in situations where other high-level languages may struggle due to their resource-hungry features.
Total Control over Hardware
One of Forth's standout features is its ability to interact directly with hardware. This low-level access allows you to harness the full potential of your embedded hardware. As an embedded systems engineer, having the capability to fine-tune and optimize every aspect of your system is invaluable. Forth gives you this power without compromising on safety or control.
Rapid Prototyping and Development
In the fast-paced world of embedded systems, time is often of the essence. Forth's interactive development environment allows for rapid prototyping and iterative testing. You can tweak code on the fly and immediately see the results, reducing development cycles and speeding up time-to-market.
Small Footprint, Big Impact
One of the perennial challenges in embedded systems is fitting functionality into a small footprint. Forth's compact runtime and efficient use of memory are instrumental in achieving this goal. It allows you to build feature-rich applications without bloating your codebase.
Real-time Capabilities
Many embedded systems require real-time responsiveness. Forth's lightweight nature and predictable execution make it well-suited for real-time applications. You can meet stringent timing requirements with confidence, knowing that Forth won't introduce unpredictable delays.
Conclusion
In the ever-evolving landscape of embedded systems development, Forth stands as a testament to the power of simplicity and efficiency. As someone deeply involved in this field, I have witnessed firsthand how Forth can revolutionize the way we approach embedded programming. Its elegance, resource efficiency, hardware control, and portability make it a compelling choice for engineers and developers alike.
If you're looking to optimize your embedded systems projects, consider embracing Forth. Its unique characteristics may take some getting used to, but the rewards in terms of code efficiency, resource utilization, and real-time capabilities are well worth the journey. Forth is not just a programming language; it's a paradigm shift that empowers embedded systems developers to do more with less.
The Elegance of Simplicity
Forth's unique approach to programming is rooted in its simplicity. It's a stack-based, postfix notation language, which may sound unconventional at first, but it's precisely this simplicity that makes it exceptionally powerful for embedded systems. In the world of constrained resources, every byte of memory and every CPU cycle count. Forth's minimalistic syntax and small runtime footprint ensure that you can do more with less.
Efficient Resource Utilization
Embedded systems often have limited resources, making memory and processing power scarce commodities. Forth's lightweight nature and minimalistic syntax allow you to make the most of these precious resources. It excels in situations where other high-level languages may struggle due to their resource-hungry features.
Total Control over Hardware
One of Forth's standout features is its ability to interact directly with hardware. This low-level access allows you to harness the full potential of your embedded hardware. As an embedded systems engineer, having the capability to fine-tune and optimize every aspect of your system is invaluable. Forth gives you this power without compromising on safety or control.
Rapid Prototyping and Development
In the fast-paced world of embedded systems, time is often of the essence. Forth's interactive development environment allows for rapid prototyping and iterative testing. You can tweak code on the fly and immediately see the results, reducing development cycles and speeding up time-to-market.
Small Footprint, Big Impact
One of the perennial challenges in embedded systems is fitting functionality into a small footprint. Forth's compact runtime and efficient use of memory are instrumental in achieving this goal. It allows you to build feature-rich applications without bloating your codebase.
Real-time Capabilities
Many embedded systems require real-time responsiveness. Forth's lightweight nature and predictable execution make it well-suited for real-time applications. You can meet stringent timing requirements with confidence, knowing that Forth won't introduce unpredictable delays.
Conclusion
In the ever-evolving landscape of embedded systems development, Forth stands as a testament to the power of simplicity and efficiency. As someone deeply involved in this field, I have witnessed firsthand how Forth can revolutionize the way we approach embedded programming. Its elegance, resource efficiency, hardware control, and portability make it a compelling choice for engineers and developers alike.
If you're looking to optimize your embedded systems projects, consider embracing Forth. Its unique characteristics may take some getting used to, but the rewards in terms of code efficiency, resource utilization, and real-time capabilities are well worth the journey. Forth is not just a programming language; it's a paradigm shift that empowers embedded systems developers to do more with less.
Next, learn how to do simple arithmetic in Forth.