Development Tools: Assemblers and Disassemblers  Projects  Code  Resources  Tools  Forum

**  Links to Program Homepages

  • A6 - Simon Collis has written a multiplatform 6502 cross-assembler geared towards Commodore 64/128 development. Executables and source code of A6 are available for DOS, Unix, and AmigaOS.
  • ACME - Marco Baye's ACME cross-assembler has been recommended by several 6502.org visitors. This assembler has been ported to several platforms including Amiga, DOS, and Linux. It supports convenient features like macros and local labels, and assembles for the 6502, 65C02, and 65C816.
  • DASM - A cross-platform, versatile macro assembler with support for target microprocessors including 6502, 68HC11, 68705, 6803, HD6303, F8 and 6507. Full source-code and selected target-machine runtimes are included in the distribution package.
  • DCC6502 - A code disassembler for the 6502 microprocessor. It features accurate cycle counting, fast table-based disassembly, portability, and special features for NES developers.
  • HXA - Anton Treuenfels' Hobby Cross Assembler (HXA) is a program written in the TAWK language. It currently handles 6502, 65C02/R65C02/W65C02S, and W65C816S instruction sets, does macros, includes, conditional assembly, and more. Its source code is available under the GNU Public License.
  • MAS65: 6502 Macro Cross Assembler - Douglas Beattie wrote this macro cross-assembler for use with his DIY-6502 homebuilt computer, and also has a version of figFORTH that support communication through the 6551 ACIA.
  • SB-Assembler - San Bergmans created this cross-assembler for DOS that includes some interesting features like a random-fill directive and multi-processor support.
  • xa65: 6502 Cross Assembler - Andre Fachat's open-source assembler is written in C and supports the standard 6502 opcode list, as well as the Rockwell R65C02 CMOS opcodes. It now supports the 65816 instruction set thanks to Jolse Maginnis. xa65 has a C-alike preprocessor and supports label-hiding in a block structure. It produces plain binary files, as well as special o65 object files. Further tools include a linker, file and relocation utilities for o65 files.
  • ATasm: A Mostly Mac/65 Cross-Assembler - Mark Schmelzenbach has created this 6502 cross-assembler that is compatible with the original Mac/65 macro-assembler from OSS software. It is specially designed for Atari computers and emulators.
  • 6502/Microlab Assembler - David Jordan has written this very simple assembler for use with the EPE Microlab trainer board. This page contains the Linux 2.x binary and C source code.
  • MXASS - A shareware cross-assembler which supports the 6502, 65C02, illegal 6502, 65816, and Z-80. It can handle macros, local labels, and many other things. A demo version is available on this site from the author, Michael Steil.
  • 6502/10 Peephole Optimizer [archive.org] - Daniel Dallmann created this C program to aid development with his C64 operating system "Lunix". The peephole optimizer works with standard 6502 code and the source is very portable.
  • WLA DX - Ville Helin is a Finnish progammer that has written "Yet Another GB-Z80/Z80/6502/6510/65816 Macro Assembler Package" that runs on several platforms including MS-DOS, Linux, and the Amiga.
  • Piotr Fusik's XASM - A portable, open source assembler. Although geared towards Atari 8-bits, it may be used for other 6502 applications as well.
  • P65 Assembler - Michael Chapman Martin has written a highly-portable 6502 cross-assembler written entirely in Perl.
  • Charles R. Bond's Assembler - A four pass assembler for the 6502 that is bundled with a source code generator that can read "H6X" files and generate assembly source.
  • Win2C64 - Aart Bik has written a 6510 cross-assembler for Windows. It supports the undocumented opcodes as well as most commonly used directives.
  • Dev65 - Andrew Jacobs has written the Dev65 Portable 65xx Development System, supporting 65xx, 65C02 and 65816 assembly language programming. It runs on any system with Java and the source can be found on SourceForge.
  • cc65 - Ullrich von Bassewitz maintains cc65 which is a cross development package for 65(C)02 systems, including macro assembler, C compiler, linker, and other tools. The assembler supports the 65816. It's cross platform and binaries are available.
  • Ophis assembler - Michael Martin's "Ophis" is a cross-assembler for 65xx, supporting the stock 6502 opcodes, 65c02 extensions, and syntax for the undocumented opcodes in the NMOS 6502. (Syntax for these opcodes matches those given in the VICE team's documentation.) It supports macros too. Ophis is written in pure Python and should be highly portable. Special emphasis is given toward developing Commodore 64 applications.

**  Direct Download from 6502.org

  • FASM10.ZIP - FASM is a macro-assembler written in C by as a quick replacement for 2500 AD. It has been released under GNU Public License and full source code is included.
  • PVU6502.ZIP - picoViewer 6502 version is a free interactive disassembler for PalmOS. More information can be found on the Picodoc website.
  • TASM301.ZIP - TASM 3.01 from Speech Technology is sort of the "de facto" for DOS cross-assemblers. It supports quite a few different processors, including the 6502 and 65C02.
  • IDA37FW.ZIP - IDA 3.7 from DataRescue is an excellent freeware multi-processor, interactive disassembler for DOS. It now grown to a commercial product and a link to it can be found in the Commercial Support section.