SAMdisk is an advanced, portable command-line disk image utility developed by Simon Owen. It is widely considered an “ultimate” tool by retrocomputing and digital preservation communities because it specializes in reading, writing, and analyzing nearly any soft-sectored floppy disk format.
Unlike basic disk imagers that only understand standard IBM PC formats, SAMdisk is designed to handle non-standard, custom, and legacy formats used by vintage 8-bit and 16-bit computers. Key Capabilities
Low-Level Floppy Access: SAMdisk interacts directly with the PC floppy disk controller. To achieve low-level hardware control on Windows, it requires the custom fdrawcmd.sys floppy driver.
Bypassing Copy Protections: It excels at replicating vintage copy-protection methods. It can safely read and accurately write disks utilizing mixed sector sizes, missing data fields, intentionally weak sectors, or cyclic redundancy check (CRC) errors.
Massive Container Support: It does not target just one format; it supports dozens of archived disk image extensions across multiple platforms (such as the Sinclair Spectrum, Amstrad CPC, SAM Coupé, and TRS-80).
Hard Disk & Compact Flash Imaging: Beyond floppies, it supports raw sector imaging and conversions to and from virtual hard disk formats like Hard Disk File (.hdf).
Cross-Platform Portability: It runs natively across Windows, Linux, and macOS. Supported File Formats
Instead of restricting users to one file layout, the utility serves as a bridge between dozens of legacy image containers. Notable supported input formats include:
EDSK / DSK: Extended disk images used by Amstrad CPC, Sinclair ZX Spectrum +3, and SAM Coupé.
MGT / SAD / SDF: Native disk images for the SAM Coupé British home computer.
TD0 / IMD: TeleDisk and Dave Dunfield’s ImageDisk containers used for historic PC archival.
Stream Formats: Raw hardware magnetic flux streams captured from modern preservation devices like KryoFlux, SuperCard Pro (SCP), and DiscFerret.
DMK: Complex sector formats primarily used by the TRS-80 system. Common Command Examples
Because SAMdisk is a command-line interface (CLI) tool, operations are completed using fast, explicit terminal commands: Command Syntax Description Read Floppy to Image SAMdisk a: image.dsk
Copies the physical floppy in drive A to a digital .dsk file. Write Image to Floppy SAMdisk image.dsk a:
Formats and burns a digital disk image back onto a physical floppy. Fast Write (No Format) SAMdisk image.dsk a: –no-format
Bypasses formatting to write faster if the disk is already formatted. Scan Disk Layout SAMdisk scan a:
Analyzes and outputs structural data like sector count, track layouts, and errors. Show Image Info SAMdisk info image.dsk
Displays track range, geometry, data rates, and sectors per track. List Connected Drives SAMdisk list
Shows a list of connected hard disks, flash drives, and block devices. Target Systems Supported
While highly flexible, SAMdisk is most frequently utilized by archivists preserving software for specific retro platforms:
simonowen/samdisk: A portable disk image utility … – GitHub
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