Only the Covert Bitops Loadersystem, NinjaTracker, SadoTracker and GoatTracker Tweak Utility are actual C64 programs; rest of them require a 32-bit Unix-like system or Windows.

C64 Tools collection

Contains several background graphics editors, 2 sprite editors and several other commandline utilities. Precompiled binaries for Win32 only but verified to compile also under Linux. The utilities use SDL library for lowlevel support.

Download for Linux
Download for Amiga OS4

Covert Bitops Loadersystem V3.06

New version of the loadersystem that is designed for a small runtime and one-time only initialization, but is more limited than V2.x. Based on the loader used in MW ULTRA. Also free to use and customize for all kinds of C64 productions. Differences / limitations compared to V2.x:

  • Separate fastloader protocol (ELoad) on SD2IEC
  • Only supports 2-bit fastload transfer protocol
  • Only supports 2-letter hexadecimal filenames
  • No built-in load under IO support
  • Sprite Y-range on screen can be set to allow loading with sprites on
  • One-time init, runtime part is less than one page of memory
  • Files to be saved must be preallocated on disk
  • For performance, desired $01 value for main program is assumed to be $35 (Kernal off)
  • Modular source code. Full file loading (compressed/uncompressed) as separate modules
  • V3.06 adds option to exclude save routines to reduce size.


    Covert Bitops Loadersystem V2.29

    A loader/depackersystem that is free to use and customize for all kinds of C64 productions. Features include:

  • Autodetects whether fastloading can be used and if the device used is a serial device or not
  • Fastloader support on 1541, 1571, 1581, CMD FD and CMD HD drives
  • "Fake" IRQ-loading on IDE64 and "fast drive emulation", see documentation for details
  • Use of 2-letter or long filenames
  • Loading of unpacked files, or those compressed with Exomizer 1/2/3 or pucrunch
  • Option to use 2-bit fastloader protocol (faster speed, but delays interrupts and no sprites allowed)
  • V2.29 fixes occasional hang on NTSC machines with the 1-bit protocol.


    Old versions of the loader (not recommended):
    Download V2.12
    Download V2.05

    DASM Win32 & Linux port

    This is an unofficial port of the DASM crossassembler by Matthew Dillon (modified by Olaf Seibert), with some fixes, including better error handling. See also the DASM official home page, the latest version from there should compile CovertBitops productions also, when used in conjunction with an updated C64 Tools collection.


    GoatTracker 2 / GoatTracker 2 Stereo

    This is a crossplatform C64 music editor. Supports output via Dag Lem's reSID engine, the HardSID 4U USB device & HardSID soundcards or CatWeasel MK3.

    From V2.0 onwards the editor includes more powerful step-programming (wave/arpeggio, pulse and filter), 63 instruments, more instrument parameters & pattern commands. May be less userfriendly than V1.xx, but you can import V1.xx songs and instruments to see how the corresponding V2 features work. Rastertime usage has stayed about the same. Also available in stereo.

    The latest Windows releases are at the project's SourceForge page and also at csdb.

    GoatTracker 2 SourceForge project
    Download for Debian
    Download for Mac

    GoatTracker V2.x Tweak Utility

    A C64 program that loads/saves GoatTracker2 song files and allows editing of the song data (orderlists, patterns, instruments, tables). NOTE: loads only GT V2.59+ song format (GTS5), so re-save your old songs first!


    NinjaTracker V2.04

    A C64 music editor with quite minimal featureset. Changes to previous versions include commands (also used as instruments), 2-column tables and a slide function that stops at target pitch. As before, allows to save both normal executable musicdata and gamemusic data without the player.

    V2.04 fixes transpose not resetting when playback is started from the beginning.


    GoatTracker2 to NinjaTracker2 converter V1.03

    Utility that converts GoatTracker2 songs to NinjaTracker V2.03+ format with some limitations. Songs that work within the limitations can then be played back with less memory and rastertime consumption.

    V1.03 adds a source format converter to not have to use the native NinjaTracker2 to save playable modules.



    A minimal / feature-stripped playroutine aiming at 9 rasterline execution time. Contains also sound effect support. No editor, published only as source code. Includes a GoatTracker2 song conversion tool similar to the GT2 -> NT2 converter.

    Github repository

    MiniPlayer 2

    An updated version of the original MiniPlayer, aiming at 9-10 rasterline execution time. Does not skip wavetable execution when reading new note data for better music quality, and adds ADSR change commands, but requires a large zeropage variable area and page alignment of music data; music data may be larger than in the original MiniPlayer.

    Github repository


    A nice & simple C64 music editor written in 1999. Music for Advanced Action Movie Simulator, Escape From New York & Metal Warrior 2 has been done with this program.


    SIDDasm V1.0

    Written by Gufino, this program produces disassembler output of .SID music files, so that you'll be able to see the musicroutine code. Both DOS & Linux versions available, with source code included.

    Download for DOS
    Download for Linux

    SIDDump V1.08

    An utility that executes .SID file player code and outputs SID chip register & note data. Note that illegal opcode support is lacking, only enough to make John Player tunes work, and also the player enviroment is far from correct (basically just the CPU and 64kB of empty RAM)

    V1.08 fixes CPU emulation issues.

    Github repository


    A quick & dirty HVSC playroutine identity scanner. Playroutine signatures can be controlled via a configuration file. Additional signatures by Yodelking, Ian Coog, ice00, Ninja & Wilfred/HVSC.

    Github repository

    GoatTracker V1.xx and related

    GoatTracker V1.53 Stereo Download
    GoatTracker V1.53 Download
    GoatTracker V1.25 Download
    GoatTracker V1.xx Tweak Utility Download
    GoatTracker V1.xx -> NinjaTracker converter Download

    NinjaTracker V1.xx

    NinjaTracker V1.1 Download
    NinjaTracker V1.02 Download

    BME library

    Not C64-related in itself, it's a graphics/sound/input library that the graphical utilities use, using in turn SDL library for lowlevel support. Contains 100% C code and should be endian-independent. The library and required include files come also with the editors but this package contains the full source for the library itself.



    Neither is this C64-related, it's a very simple console application multitrack recording program (up to 12 tracks, 48 kHz). Works in 32-bit Windows only.