IMG.CFG Configuration File

FlashFloppy can usually automatically determine the layout of IMG/IMA files, based on their size and (optionally) a hint about the host they target (FF.CFG: host=).

However, there are such a wide range of systems that FlashFloppy cannot hope to support them all automatically. For example, the CP/M operating system does not have a standard disk layout, and these systems among others require a degree of manual configuration.

The solution is an INI-style configuration file called IMG.CFG, placed in the root folder or FF/ subfolder of your USB drive. An example is provided in the examples/ subfolder of the FlashFloppy distribution.

Tags

The file is divided into sections, each starting with a tag name in square brackets. This section defines the track layout (geometry) for all images named *.tagname.img and *.tagname.ima.

An optional [default] section can be defined, which matches all IMG/IMA files that do not match any other defined tag, including untagged files (ie. *img and *.ima).

If an IMG/IMA file does not match any tag, and no default tag is defined, FlashFloppy uses normal geometry auto-detection based on the file's size and the optional host= setting in FF.CFG.

Geometry Options

Within each tagged section, a set of geometry parameters, mandatory and optional, are specified. These are listed below.

For optional parameters, the default values are marked by asterisk.

• cyls = 1-254 (Mandatory)

  • Number of cylinders

• heads = 1-2 (Mandatory)

  • Number of heads (aka sides)

• secs = 1-256 (Mandatory)

  • Number of sectors per track

• bps = 128 | 256 | 512 | 1024 | 2048 | 4096 | 8192 (Mandatory)

  • Data bytes per sector

• id = 0-255[:0-255] (1*)

  • ID of the first sector on each track
  • Successive sectors are numbered sequentially upwards
  • Numbers may be expressed in hexadecimal with 0x prefix (eg. 0xab).
  • Format x:y allows specifying different ID (x, y) for each head/disk-side.
  • Format x specifies same ID (x) for both heads/sides of a double-sided disk.

• mode = fm | mfm*

  • Recording mode

• interleave = 1-255 (1*)

  • Sector interleave (default is 1:1, which is no interleave)

• cskew = 0-255 (0*)

  • Sector skew per cylinder (default is 0, which is no skew)

• hskew = 0-255 (0*)

  • Sector skew per head (default is 0, which is no skew)

• rpm = 1-1000 (300*)

  • Rotational RPM

• gap3 = 0-255 (0*)

  • Sector post-data gap, in bytes.
  • N=0: Auto-select based on recording mode, sector size, and size of track

• iam = yes* | no

  • Index Address Mark included at the start of each track?

• rate = 0-1000 (0*)

  • Data rate in kHz (kbit/s).
    • eg. 250 is MFM DD, 500 is MFM HD, 125 is FM SD.
  • N=0: Auto-select based on recording mode and size of track

• file-layout = interleaved* | sequential | reverse-sideN | sides-swapped

  • Image file track layout
  • Multiple values can be specified, separated by commas (eg. sequential,reverse-side1)
  • sequential: Sequential cylinder ordering: all side 0, then side 1
  • interleaved: Interleaved cylinder ordering: c0s0, c0s1, c1s0, c1s1, ...
  • reverse-sideN: Side-N cylinders are in reverse order (high to low) (N=0,1)
  • sides-swapped: Sides 0 and 1 ordering is swapped in the image file