The universal Atari assembler

rg-asm

Universal 680x0 and DSP 56k assembler targeting Atari systems.

Loading release…

Key features

  • Universal Input: Works with all existing Atari assembler source code: vasm, Devpac, Pure C, TurboAsm, Seka, GAS, MADMAC, RMAC, Alcyon and more.
  • Universal Output: Built in linker, can assemble to a runnable PRG, or emit objects for vbcc / gcc / AHCC. Flat binaries and mixed object formats in one link.
  • Motorola DSP 56001: Standalone assembly for Atari Falcon DSP kernels, with support for all the key output formats.
  • Seamless Mixed-Mode: Embed DSP56001 code directly within 680x0 source files, sharing symbols, equates, and structured data offsets.
  • Universal CPU: Supports the full 680x0 line — 68000 through 68060, Floating Point Units (68881/68882), all ColdFire models, and the Motorola DSP56001.
  • Universal Binaries: Cross compile from native binaries for Linux, macOS (Arm + Intel) and Windows. Single executable. No dependencies. Download, unzip and run.
  • Complete Syntax: Macros, conditionals, incbin, org/sections, equates, alignment and linkage. Supports every atari assembler syntax on the planet.
  • Warnings & Errors: Graduated severity, promote or silence categories, enumerate every diagnostic kind.
  • Diagnostics & Metrics: See the cost of every instruction, on every CPU. Per function breakdown of cycle and byte cost. Every metric can be output to json to be processed by other tools.
  • 68k Inside: rg-asm is built around a full 68k emulator, so it can fully understand every instruction. Handles smallest size optimisations and conventional peephole optimisations. Can even reorder instructions to benefit from pipeline pairing.
rg-asm; assemble 
 
  █▀▀▄ █▀▀▀
  █▀█▄ █ ▀█   RESERVOIR GODS
  ▀  ▀ ▀▀▀▀   rg-asm 0.8.8 · 680x0 & DSP 56k assembler
 
  ✓ Assembling hello_gemdos.s
  ✓ Linking HELLO.PRG (136 bytes)
  ✓ assembled 1 file in 80ms
 
┌────────┬───────┐
│ item   │ bytes │
├────────┼───────┤
│ text   │    26 │
│ data   │    22 │
│ bss    │     0 │
│ sym    │    56 │
│ reloc  │     4 │
├────────┼───────┤
│ binary │   136 │
└────────┴───────┘
$

Quick start

rg-asm main.s util.s                           # assemble and link → MAIN.PRG
rg-asm --obj main.s util.s                     # emit objects for C linkers
rg-asm --raw boot.s -o BOOT.BIN                # emit flat binary blob
rg-asm --cpu=56001 kernel.s56 -o KERNEL.LOD    # standalone Falcon DSP kernel
rg-asm --cpu=56001 --format=p56 sfx.s56 -o SFX.P56 # Brainstorm P56 format
rg-asm --cpu=56001 --format=dsp job.s56 -o JOB.DSP # GODLIB sDspBinary (fast 68030 blast)
rg-asm falcon_game.s                           # 68k + inline DSP mixed-mode assembly
rg-asm game.s --listing --functions --listing-cpus=68000,68030
rg-asm game.s --listing=game.lst --listing-cpus=68000,68030   # plain .lst file

On a terminal, bare --listing paints the boxed table; a file path stays plain text for CI.

Verify

After unzipping, check the extracted files (the archive includes SHA256SUMS):

sha256sum -c SHA256SUMS

Learn more