libdskrc - Man Page

Custom format definitions for LibDSK programs


The libdskrc file contains definitions of disk  geometries, which can be used by the LibDsk utilities dsktrans(1) , dskid(1) and dskform(1)

The file consists of one or more sections, each describing one disk layout. Each section begins with the format name in square brackets, and  continues until the next section begins. Within each section are one or more  entries of the form

variable = value

Anything after a semicolon or hash   character is treated as a comment and ignored. Blank lines are  also ignored.


For each geometry, the entries listed below can be present. If not  all the values are present, LibDsk will use default values from its "pcw180" format (40 tracks, 9 sectors, single-sided, MFM).

description = DESC

The description of the format as shown by (for example) dskform --help.


How a double-sided disk is handled. This can either be alt (sides alternate -- used by most PC-hosted operating systems), outback (use side 0 tracks 0-79, then side 1 tracks 79-0 -- used by 144FEAT  CP/M disks), or outout (use side 0 tracks 0-79, then side 1 tracks 0-79 -- used by some Acorn  formats). If the disk is single-sided, this parameter can be omitted.

cylinders = COUNT

Sets the number of cylinders (usually 40 or 80).

heads = COUNT

Sets the number of heads (usually 1 or 2 for single- or double-sided).

sectors = COUNT

Sets the number of sectors per track.

secbase = NUMBER

Sets the first sector number on a track. Usually 1; some Acorn formats use 0.

secsize = COUNT

Sets the size of a sector in bytes. This should be a power of 2.

datarate = VALUE

Sets the rate at which the disk should be accessed. This is one of HD (1.4Mb or 1.2Mb),  DD (360k or 720k disc in 1.2Mb drive), SD (360k or 720k disc in 1.4Mb, 720k or 360k drive), ED (2.8Mb).

rwgap = VALUE

Set the read/write gap.

fmtgap = VALUE

Set the format gap.

fm = Y or N

Set the recording mode. Y for FM, N for MFM.

multitrack = Y or N

Set multitrack mode; this only affects attempts to read normal data from tracks containing deleted data (or vice versa). Y for yes, N for  no.

skipdeleted = Y or N

Skip deleted data when searching for non-deleted data (or vice versa). Y for yes, N for no.



User-specified format list.


System-wide format list.

See Also

dsktrans(1) , dskform(1) , dskid(1)


John Elliott <>.


20 January 2006 Version 1.2.1 Emulators