FS(4) COMMAND REFERENCE FS(4) NAME fs - standard floppy disk driver for SCSI floppy disk drives DESCRIPTION The fs device provides access to the standard flexible disk drive. It uses 5 1/4 inch, double-sided, double- or high- density, soft-sectored, pre-formatted flexible disks. The characteristics of the two supported media are: Type Double-density High-density ________________________________________________ tracks/inch 4 96 bytes/sector 512 512 sectors/track 9 15 tracks/side 40 80 sides/diskette 2 2 bytes/diskette 368640 1228800 sectors/diskette 720 2400 Both formats are compatible with the de facto industry standard for Personal Computing media. When the fs device is opened, UTek tests the diskette to see whether it is formatted as a double-density or high-density medium. It performs all operations on the diskette in the appropriate mode, until the device is reopened. If the diskette is not formatted, only the whole disk partition may be opened, and the only operation allowed is formatting. The standard name for the flexible disk is fs02. Device naming conventions specify a two-letter description of the device, followed by the slot number, followed by the device number. The slot number for the standard floppy disk drive is 0 since its SCSI interface is on the main board. The device number for the standard floppy disk drive is 2 since it is configured as the first unit at SCSI bus address 1. Although floppy disks are not actually partitioned, they are accessed as if they follow the partitioning scheme for hard disks. Only partitions a and p (appended to the device name) are accessible. Partition a refers to all of the data space and is used for all normal data operations. Partition p refers to the whole disk and is used for formatting operations. The flexible disk may only be accessed in character (raw) mode. The character device name is the standard name with an r prefixed. Standard device names rdf and IB rdfp are linked to rfs02a and rfs02p, respectively, for ease of use and compatibility with previous UTek products. Printed 5/12/88 1
FS(4) COMMAND REFERENCE FS(4) Use scsifmt(8) on /dev/rdfp to format floppy disks. This can be done at any time. UTek does not support access to the block floppy device due to concerns for system integrity. FILES /dev/rfs02a, /dev/rdf raw files /dev/rfs02p, /dev/rdfp formatting /dev/fs02a, /dev/df block files DIAGNOSTICS The following errors may be returned. [EBUSY] Drive not ready (on a read or write). [ENXIO] Nonexistent drive (on open); or (on a read or write) offset is too large or not on a sector boundary. [EIO] A physical error other than ``not ready''. CAVEATS Due to limitations of the electrical interface between the controller and drive, the fs driver is unable to determine directly what capacity drive or floppy disk is being used. Operation mistakes such as formatting a high-density diskette as double-density or vice versa can't be prevented. The former mistake will lose capacity; the latter will lose data integrity or create data errors. The only way that the driver can determine capacity is to examine the readability of the formatted diskette. The high-capacity floppy drives shipped as the standard floppy drive on all workstations with a standard SCSI interface are capable of reliably reading and writing double- and high-density diskettes. Due to limitations of the electromechanical design of the high-capacity drives, standard (360K only) drives can't reliably read double- density (360K) diskettes written by such drives. SEE ALSO ds(4), diskpart(5), and scsifmt(8). Printed 5/12/88 2
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