FSIO-DOSMT(1)

NAME
fsio-dosmt - Foreign File System I/O - DOS-11 magtape

DESCRIPTION
fsio allows access to DOS-11 magtapes using the file system type "dosmt"

WILDCARD CHARACTERS
The wildcard character '*' may be used to match filename, extension, group number and user number. Wildcard characters may be used with the dir command to limit the number of files being displayed. They may also be used with commands to read files; dump, type and copy (only the source file for copy), in which case the next file which matches the wildcard character(s) will be used for input. As a consequence of this, the empty filename may be used to select the next file on the tape, so:
    fsio> type mt:
will type the next file on the tape.

MOUNT OPERATION
DOS/BATCH-11 defined magtape headers to be 14 bytes long with 2 bytes unused. Some tapes use these unused bytes to add an additional 3 characters to the filename (e.g. ABCDEFGHI.EXT rather than ABCDEF.EXT). By default, fsio will ignore these unused bytes. If the -x switch is used on the mount command, fsio will make use of the extra 3 characters on file lookup, directory listing and file creation.

NEWFS OPERATION
newfs creates an empty (zero length) file.

SET OPERATION
The following set commands are supported:

uic [proj,prog]
    Sets the default UIC for file access (was [1,1] after mount).
        proj - Project number (octal 1 - 377)
        prog - Programmer number (octal 1 - 377)

prot <code>
    Set the default protection code when writing new files to magtape.
        prot - Protection code (octal 0 - 377)

INFO OPERATION
info displays where the tape is currently positioned. If the tape is not positioned at the end and it is not an empty tape, the name of the next file after the current position will be displayed.

NOTES
DOS-11 magtapes differ from disk-based file systems in a number of ways:
    1. Filenames are not unique on a magtape.
    2. The tape has to be positioned before writing a new file to
       avoid over-writing an existing file.
Assuming a magtape is mounted on mt: and has 5 files on it:
The sequence:
    fsio> rewind mt:
    fsio> copy -a a.b mt:c.d
will result in the tape containing a single file (c.d), while the sequence:
    fsio> eom mt:
    fsio> copy -a a.b mt:c.d
will result in the tape containing 6 files (the original 5 followed by c.d).
By using skipf/skipr commands it is possible to position the tape just past the end of any specific file (see info command for more details on how to determine the current tape position).

SEE ALSO
fsio(1) fsio-dos11(1) fsio-rt11(1) fsio-os8(1)

AUTHOR
John Forecast, <john@forecast.name>