A downloadable tool for Windows, macOS, and Linux

Download NowName your own price

JC64dis (next generation C64 disassembler) is an iterative disassembler for MUS, SID and PRG file of Commodore 64.

It works with 3 area:

  1. Memory area (from $0000 to $FFFF)
  2. Preview of source
  3. Source

You can formatting the source using the commands in a way to produce a source like if you were writing it in a text editor.

Labels and some comments are created automatically, but you can customize all.

In the video you can see a true session of usage where a binary is reverse engineered into a source that can be compiled again.

Binary are in jar (java) or specific for Windows (win32 o win64)

Source code at: https://github.com/ice00/jc64

Provided example obtained from reverse engineering some PSIS files:

  • Music Assembler player (tune "MC_01" by Marco Swagerman (c) 1988 Dutch USA Team )
  • Music Assembler player (tune "Magazine Intro Tune" by Reyn Ouwehand (c) 1989 Reyn Ouwehand
  • Voice Tracker player (tune "3LUX Intro" by The Bill (c) 1993-95 3LUX")
  • Music Mixer player (tune "Michael" by Arkadiusz Zych (Smart Monkey) (c) 1991 Silver Dream
  • Ryo Kawasay player (tune "Kawasaki Synthesizer Theme Song" by Ryo Kawasaki (c) 1983 Sight&Sound Music Software)
  • Kawasaki Synthetizer player (tune "Major" by Ryo Kawasaki (c) 1983 Sight&Sound Music Software)
  • Matt Gray player (tune "Serpent Demo" by Matt Gray (c) 1987 Matt Gray)
  • Ten-Tracker player (tune "Ten Tracker Test" by Sebastian Bachlinski (Moog) (c) 1991 Keen Acid)
  • SoundMonitor player (tune "Shades (filter corrected)" by Chris Hülsbeck (c) 1986 Markt & Technik)


Download NowName your own price

Click download now to get access to the following files:

jc64dis-java.zip 8 MB
jc64dis-win32.zip 44 MB
jc64dis-win64.zip 113 MB

Development log


Log in with itch.io to leave a comment.

Expect version 0.8 soon (being testing right now). Version 0.7 has a (wrong) 20KB limit instead of 65KB in input file.

Added even new features..