ATasm v1.09

A mostly Mac/65 compatible 6502 cross-assembler

Copyright (c) 1998-2021 Mark Schmelzenbach, modified by Peter Hinz (2021)

ATasm is a 6502 command-line cross-assembler that is compatible with the original Mac/65 macroassembler released by OSS software. Code development can now be performed using "modern" editors and compiles with lightning speed.

ATasm Features

• ATasm produces Atari native binary load object files or can optionally target .XFD/.ATR disk images and the machine state files produced by the Atari800Win emulator (version 2.5c or greater),the Atari800 emulator (version 0.9.8g or greater) or the Atari++ emulator (version 1.24 or greater)
• Conditional code generation, and code block repetition
• Rich macro support, compatible with existing Mac/65 code libraries
• Atari specific assembler directives (.SBYTE,.FLOAT,etc.) and undocumented opcodes.

ATasm runs native on IBM PCs in Windows and compiles cleanly under Linux, MacOS/X or any platform with the GNU C or Clang compiler.

All source code and the Windows binary are included in the package.