NAME

flpop − specify parameters on variable fdc devices

SYNOPSIS

flpop [ −o ] [ device-type ]

DESCRIPTION

Flpop is a screen-based program for setting the physical layout parameters of the variable-format devices /dev/[r]fdv{1024,512,256} to emulate the sector layouts of foreign disc formats not otherwise supported under Acorn UNIX. The parameters so set are not reset until asked for or the system is rebooted. 

The device-type parameter specifies which of the three available variable-format devices is to have its parameters set.  If no parameter is given, the type is taken from the value of the environment variable FLOPPY, if it is defined; otherwise the type 1024 is used.  Whichever way the type is determined, it must be specified simply as one of the strings 1024, 512 or 256 to select the corresponding device: /dev/rfdftype. The initial layout settings (at boot-time) for each of these devices are the same as the settings used by the corresponding fixed format device /dev/[r]fdf{1024,512,256}. (Note that the variable format device names are slightly misleading in that it is possible to set a sector length for a device other than that implied by its name.)

If the −o option is used flpop will display the existing set of parameters, otherwise the device will be reset to its default values.  The user can step through the values displayed, pressing return to accept the existing parameters, or overtyping a new value. 

Disc Unit provides another opportunity to select the disc unit other than from the argument or from the environment variable. The user is prompted as to whether he wants the unit to be initialised to the boot-time values. 

Bytes/sector may be 256, 512 or 1024.  Note that as mentioned above this parameter is not constrained to match the disc unit name. 

Sectors per track and Tracks per surface are hopefully self-explanatory. 

Sector numbering starts at may be set to 0 or 1 according to whether the sectors are numbered 0 to n-1 (as in ADFS diskettes), or 1 to n (as in MS-DOS diskettes). 

Surface access may be surface, to denote that all of side 0, then all of side 1 is used, cylinder, to denote that alternate sides are used, or folded, to denote that access is forward on side 0 and backward on side 1.

Apply interleave on format/read-write may be set to format, to denote that sector interleaving is applied when the diskette is formatted, or when the diskette is read or written. 

Interleave gives the sector interleave on a track. 

Skew gives the inter-track skew. 

Initial track is usually zero, however some machines insist on starting at track 1, working to the end and then using the track zero. This option provides for this. 

FILES

/dev/rfdv{1024,512,256}

SEE ALSO

adfsls(1), adfscat(1), adfscp(1), wradfs(1), msdosls(1), msdoscat(1), msdoscp(1), wrmsdos(1), fdc(4), ffd(8). 
 

7th Edition  —  Revision 1.6 of 15/12/88