SAMdisk — SAM Coupé

Despite using the same flexible WD1772 FDC chip as the Atari ST, the majority of SAM disks formats aren’t particularly challenging.

Floppy to Image

To create a disk image from an existing SAM disk use:

SAMdisk a: image.dsk

Image to Floppy

To write a SAM disk image back to a real disk use:

SAMdisk image.dsk a:

To write a disk image to a pre-formatted SAM floppy (faster):

SAMdisk image.dsk a: --no-format

To write only used tracks to pre-formatted floppy (fastest!):

SAMdisk image.dsk a: --minimal --no-format

Format Floppy

To format a floppy in MGT format for normal SAM use:

SAMdisk format a:

To format a floppy in CP/M format for Pro-Dos use:

SAMdisk format a: --cpm

Note: Be sure to use only true double-density disks, which should be marked DSDD or 2DD, and are often blue. Covering the hole on high-density disks (usually black) is not recommended!

Atom / Atom Lite

BDOS format drives are supported, on floppy disks, hard disks, or compact flash cards.

List Drives

To display a list of available drives:

SAMdisk list

Sample output:

 Name:      ST380021A
 Capacity:  80026361856 bytes = 156301488 sectors = 80GB
 Name:      Generic-Compact Flash
 Capacity:  524869632 bytes = 1025136 sectors = 525MB
 Format:    Atom Lite, 641 records, bootable

A drive number followed by a colon is shown above each entry, and used to refer to the drive in other commands. In this example the OS boot drive is 0: and the BDOS drive is 1:

List Records

To list the BDOS records on this drive:

 SAMdisk list 1:

Sample output:

 Atom Lite, 641 records:

    1 : System
   10 : Comet v18
   40 : SAM Paint
   50 : Lemmings! 1-1
   51 : Lemmings! 1-2

List Files

To show a directory listing of files in a single BDOS record (1 in this example):

SAMdisk list 1:1

Sample output:

Record 1: System

 1* Mini-FAT16  256  SPECIAL
 2  AL-BDOS15a   21  CODE  32777,10701         22/07/2012 00:59
 3  AL-LOGO      49  SCREEN$ [mode 4]          22/07/2012 00:59

3 files, 77 free slots,  163K used, 617K free


Drive to Image

To create a disk image from a BDOS drive:

SAMdisk 1: image.hdf

The output file is uncompressed, so you’ll need space matching your source drive size.

Image to Drive

SAMdisk image.hdf 1:

You’ll be asked to confirm the target drive is correct before writing begins, though you may skip this step with --force if you need to automate this process.

If your target drive is a different size (even slightly), use --resize to make the necessary adjustments. This is not the default behaviour as a safety precaution.

If your new drive is much larger than the old one, you can use --quick to skip the zero-filling of the new disk after the content is copied.

To convert between Atom and Atom Lite formats during the write, use --byte-swap.

Image to Image

To convert images between Atom and Atom Lite format requires byte-swapping:

SAMdisk atom.hdf atomlite.hdf --byte-swap

To copy an image into a existing image of a different size will require resizing:

SAMdisk small.hdf big.hdf --resize

Create Image

To create a blank HDF disk image (32MB in this example):

SAMdisk create image.hdf 32

This image will still need formatting before use.

Format Drive or Image

To format a drive or image for use with the Atom Lite interface:

SAMdisk format 1:
SAMdisk format image.hdf

To format for use with the legacy Atom interface:

SAMdisk format 1: --atom:


Format Record

To format an existing record, to empty it:

SAMdisk format 1:123

Record to Image

To copy a record (123 in this example) to a floppy disk image:

SAMdisk 1:123 image.mgt

To copy a special ProDos CP/M record to a disk image:

SAMdisk 1:123 image.cpm --cpm

Image to Record

To copy a disk image (MGT or compatible) to a record:

SAMdisk image.mgt 1:123

To copy a 720K CP/M image to a the special ProDos record format:

SAMdisk image.cpm 1:123 --cpm

Record to Record

To copy between records is simple too:

SAMdisk 1:123 1:234

Boot Sector

The first sector on a BDOS drive is the boot sector, which holds configuration parameters for the drive, as well as code to load the splash screen and optionally auto-boot a record.

Boot to File

To copy the boot sector a file:

SAMdisk 1:0 image.bin

File to Boot

To copy a previously saved boot sector (512 bytes) back to the drive:

SAMdisk image.bin 1:0

SAMdisk will automatically update the BDOS parameters in the data before writing. To suppress this add --no-fix.