Greasweazle

Usage Overview (Yann Serra Tutorial)

The following condensed guide is based on a tutorial by Yann Serra, contributed to the Greaseweazle project documentation in April 2023.

Hardware Compatibility

Greaseweazle supports standard Shugart and IBM floppy drives:

• **3.5-inch** and **5.25-inch** drives with a 34-pin connector
• **3-inch Amstrad** drives (26-pin, via adapter)
• **8-inch** drives (50-pin, via adapter)

Commodore (non-Amiga) and Apple Macintosh drives are not directly supported, but their media can often be read/written using a compatible standard-interface drive. Certain GCR formats (Apple II/Mac, Commodore 64) may require trial-and-error to find a drive with correct bitcell timing.

Drive Cabling

• **IBM standard**: Two drives per cable with a twist; end = drive A, middle = drive B.
• **Shugart standard**: Flat cable; drive ID set via jumpers (DS0/DS1/DS2). Supports up to three drives.

Access Levels

1. **Sector-level** – Block-mode images (.img, .adf, .st) containing user-accessible data. 2. **Track-level** – Includes format metadata (.imd, .edsk) preserving sector layout, gaps, and copy-protection markers. 3. **Flux-level** – Captures raw magnetic transition data (.scp, .hfe) for exact reproduction.

Basic Commands

Read disk to image:

gw read --format=amiga.amigados MyAmigaDisk.adf --drive=A

Write image to disk:

gw write --format=amiga.amigados MyAmigaDisk.adf --drive=A

Omitting --format and --drive uses defaults based on file extension and drive A.

Supported Disk Profiles

Greaseweazle includes predefined format profiles covering dozens of platforms (Acorn, Amiga, Atari ST, Commodore, IBM PC, Macintosh, MSX, NEC PC-98, ZX Spectrum, and others). Each profile defines:

• Physical geometry (cylinders, heads, RPM)
• Encoding type (FM, MFM, GCR)
• Sector size and count

Preferred image suffixes depend on the format (e.g., .adf for AmigaDOS, .st for Atari ST, .img for IBM PC). For the full list, see the tutorial source.

Troubleshooting Common Errors

• **No Index** – Incorrect drive ID, no power, or cable inserted incorrectly.
• **Track 0 Not Found** – Insufficient drive power or incorrect drive selection.
• **Flux Overflow/Underflow** – USB connection interference; try a different port/cable.
• **Verify Failure** – Possible disk surface damage; clean disk and drive heads.

Advanced Use Cases

• **Meta-profiles** (ibm.scan, raw.125, etc.) and **meta-images** (.edsk, .imd) for arbitrary sector geometries.
• Reading 48-TPI disks with 96-TPI drives using --tracks=…:step=2.
• Flux-level archiving for copy-protected or unknown formats with --adjust-speed and --raw.
• Handling “flippy” 5.25-inch disks with drives supporting --fake-index.

External Tools

Greaseweazle flux/image files can be processed with third-party utilities such as:

• **Disk Utilities** – Converts between .scp/.dfi and .ipf.
• **HxC Floppy Emulator** – Converts many exotic formats to/from .hfe/.scp.
• **SamDisk** – Works with additional meta-image formats (.sad, .sbt, .mbd, etc.).
• **a8rawconv** – Converts Atari 8-bit formats.
• **Fluxengine** – Alternative imaging tool supporting additional formats.

Custom Profiles

Format profiles are stored in diskdefs.cfg. Users can define new profiles in a custom configuration file and load them with:

gw read --diskdefs=MyFormats.cfg --format=my.disk.format MyDisk.img