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Forth-based Programming Language Designed for 6502 Central Processing Unit

Small computing devices often utilize Forth due to its simplicity and power. However, when space is critically limited, such as on a 6502, a compact version like milliForth is a viable solution.

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Small computer enthusiasts often turn to Forth due to its ease of implementation and impressive...
Small computer enthusiasts often turn to Forth due to its ease of implementation and impressive power. However, when a significant reduction in size is necessary, especially for 6502 systems, the solution is milliForth.

Forth-based Programming Language Designed for 6502 Central Processing Unit

Small computing enthusiasts will appreciate the compact 6502-friendly Forth system known as milliForth-6502. This petite powerhouse is a modified adaptation of milliForth, itself a fork of sectorforth. The sectorforth project set the bar high, producing a Forth so tiny it could fit within a 512-byte boot sector. milliForth outdid its predecessor with a leaner 336-byte build, but it was restricted to the x86 architecture. milliForth-6502, developed by Alvaro G. S. Barcellos, aims to slim down the 6502 implementation even more.

The milliForth-6502 binary clocks in at approximately 1,110 bytes in our tests – still remarkably compact but not quite a boot sector fit. The majority of the code in milliForth-6502 is written in assembly, primarily in the sector-6502.s file. To facilitate emulation, the code is compiled using tools from the cc65 project, with lib6502 serving for 6502 emulation during development and testing.

While emulation is useful, the ultimate goal is to see milliForth-6502 in action on a genuine 6502 microprocessor. Ideally, we'd love to witness this code working on a homemade 6502 system! If you manage to get milliForth-6502 running, share your triumphs with us!

Here's a simplified process for running milliForth-6502 on a real 6502 system:

  1. Download the Source Code: Obtain the milliForth-6502 source code from online repositories or project pages.
  2. Assemble or Compile the Code: Utilize an assembler or compiler compatible with the 6502 architecture, such as CA65 from the CC65 suite, to convert the assembly code into machine code.
  3. Create a Binary Image: Format the resulting machine code into a binary image that can be loaded into the system's memory.
  4. Load the Binary: Use a programmer or other method to load the binary into the memory of the 6502 system.
  5. Run the Program: Set the program counter to the starting address of milliForth-6502 and execute it, typically through a reset or specific command.

Some additional considerations for running milliForth-6502 on a 6502 system:

  • Be sure to have a suitable 6502 setup, including EEPROM or EPROM for storage and any required peripherals (e.g., serial interface for interaction).
  • Familiarize yourself with the necessary software tools for assembly and programming.
  • Consult milliForth-6502's documentation for detailed instructions and any specific requirements. Happy Forth-fying on your 6502 adventures!

In the pursuit of running milliForth-6502 on a genuine 6502 microprocessor, one must first download the source code and then use an assembler or compiler compatible with the 6502 architecture to convert the assembly code into machine code, creating a binary image that can be loaded into the system's memory. To facilitate this, tools from the cc65 project, including CA65 and lib6502, may be employed for assembly and 6502 emulation during development and testing.

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