Holonforth Systems

The Holonforth programming systems combine browser, editor and umbilical target link. And in the DOS systems also: assembler, compiler, linker, debugger and interpreter.


The user interface is a browser, which offers a permanent view of the program. All  program development is done in the browser. Editing, loading, testing, debugging. This stable environment lets you concentrate on the application without distractions.

Hierarchical program structure

Holonforth manages the source code of the program as a structure of modules (= chapters), groups (= sections) and words (= units). Related words are collected in groups, and related groups are collected in modules. The module/chapter corresponds to a text file in a conventional development environment. This structure makes the program clear to read and easy to understand.

The complete program is visible and accessible. You can browse and study the program, directly access every detail, move items around and restructure the program after a series of changes. In Holonforth it is easy to maintain the source code clear and readable.

Hypertext is intrinsic to the Holonforth method of source code management. You can directly look up every word in a definition.

Develop and test code directly in the target system

Holonforth communicates with a living target system. The Holonforth host compiles the code into the target system, ready for testing. You can try every program routine interactively, running in its real environment.

This "umbilical" method of development is well established in Forth cross development systems. Holonforth adds a new technique of meta-compilation.

Holon86 is unique; it cross-develops programs for the host platform (PC to PC); the application program is not burdened with a full Forth system. This is ideal for small utility programs, e.g. drivers.

Immediate edit-test cycle

If you change a word in the program, the new code of the word is substituted in the existing program and the change is instantly effective. The state of the program is preserved over the change (buffers remain filled, files remain open, I/O remains initialized, etc.) - there is no need to restart the program and to find your place again, thus you can test the change at once.

This lets you work in high concentration, without being interrupted by the conventional compile & restart cycles.

Special Holon86 and 11:

Single step through the source text

The debugger is integrated with the editor. Step through the code of a word and observe the steps in the source text. If you continue the execution in a subword, the editor calls up the text of the subword and marks the current step in it. Trace the execution down through the inner kernel words of the application system.

This is ideal for studying the Forth machine. 

Rich source libraries fully documented

Holonforth offers a rich set of standard Forth words and many proven utility words. All words of the system, including the innermost kernel words, are defined and documented in the source text.

Lean program code

The application only contains the code that is actually used by the program. Holonforth can load the program selectively and create very lean code. 

Hardware & software co-design

Holonforth favors the co-design of hardware and software and lets you test the hardware in early stages of the project. Holonforth uses minimal resources in the target. The Holon11 monitor runs in the internal RAM of the 68HC11 micro controller. You can contact the bare 68HC11 system before external RAM is added or working. Read and control the peripheral pins of the chip and test the hardware in progress. Use it for production testing