IMG.CFG Configuration File
FlashFloppy can usually automatically determine the layout of IMG/IMA/DSK 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.
NOTE: If FF/ exists, IMG.CFG must reside there, as the root folder isn't searched.
The file is divided into sections, each starting with a tag in square brackets of the form [<tagname>][::<filesize>]. This matches files as follows:
- <tagname> matches images of the form *.<tagname>.{img,ima,dsk}
- Missing (empty) tagname matches any *.{img,ima,dsk} which is untagged or does not match any other defined tag.
- Tagnames and their matches are NOT case sensitive.
- <filesize>, if specified, must exactly match the image filesize.
- If an image matches no tag, FlashFloppy uses normal geometry auto-detection based on the host= setting in FF.CFG.
For example, [dsdd80::737280] matches images with both:
- Name of the form *.dsdd80.{img,ima,dsk}
- Size exactly 720kB (737280 bytes).
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.
Image-scope parameters apply to whole disk images. They cannot appear in a tracks sub-section (as described below).
-
cyls = 1-255 (Mandatory)
- Number of cylinders
-
heads = 1-2 (Mandatory)
- Number of heads (aka sides)
-
step = 1-255 (1*)
- Number of drive-head steps between cylinders
- For example: step=2 simulates a 40-cyl disk in an 80-cyl drive
-
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
Track-scope parameters are by default applied to all tracks unless preceded by a tracks declaration:
-
tracks = <track-list>
- track-list ::= <track-range>[,<track-list>]
- track-range ::= <cylinder>[.<head>] | <cylinder>-<cylinder>[.<head>]
- cylinder ::= [0-9][0-9]*
- head ::= 0|1
- If no head is specified in a track-range, then all heads are assumed.
- Examples:
- 0-23.1,45.0 specifies head 1 of cyls 0-23 and head 0 of cyl 45.
- 27-33 specifies all heads of cyls 27-33.
The track-scope parameters are:
-
secs = 0-256 (0*)
- Number of sectors per track
-
bps = 128 | 256 | 512 | 1024 | 2048 | 4096 | 8192
- Data bytes per sector
- Mandatory if secs is non-zero
- May be specified as a comma-separated list if sector sizes vary
- For example: 512,512,512,512,512,512,512,512,256
-
img_bps = 0* | 128 | 256 | 512 | 1024 | 2048 | 4096 | 8192
- Bytes occupied per sector in the IMG file
- Smaller sectors will be padded
- Default is 0: Sectors occupy precisely their data size, no padding
-
id = 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).
-
h = 0|1|auto (auto*)
- Head number for all sectors on the track
- auto: Use the physical drive head number
-
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
-
gap2 = 0-255|auto (auto*)
- Sector post-ID gap, in bytes.
- auto: Auto-select based on recording mode and sector size
-
gap3 = 0-255|auto (auto*)
- Sector post-data gap, in bytes.
- auto: Auto-select based on recording mode and sector size
-
gap4a = 0-255|auto (auto*)
- Post-index gap, in bytes.
- auto: Auto-select based on recording mode and sector size
-
iam = yes* | no
- yes: 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.
- 0: Auto-select based on recording mode and size of track
- Data rate in kHz (kbit/s).