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Diffstat (limited to 'static/v10/man5/tap.5')
| -rw-r--r-- | static/v10/man5/tap.5 | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/static/v10/man5/tap.5 b/static/v10/man5/tap.5 new file mode 100644 index 00000000..2bc1171d --- /dev/null +++ b/static/v10/man5/tap.5 @@ -0,0 +1,68 @@ +.pa 1 +.he 'TAP (V)'6/12/72'TAP (V)' +.ti 0 +NAME tap -- DEC/mag tape formats +.sp +.ti 0 +DESCRIPTION The +DECtape command tap___ and +the magtape command mt__ +dump and extract files to and +from their respective tape media. +The formats of these tapes are the same except +that magtapes have larger directories. +.sp +Block zero of the tape is not used. +It is available to contain a boot program to be +used in a stand-alone environment. +This has proved valuable for DEC diagnostic programs. +.sp +Blocks 1 through 24 +for DECtape (1 through 146 for magtape) +contain a directory of the tape. +There are 192 (resp. 1168) entries in the directory; +8 entries per block; +64 bytes per entry. +Each entry has the following format: +.sp +.in +3 +path name 32 bytes +.br +mode 1 byte +.br +uid 1 byte +.br +size 2 bytes +.br +time modified 4 bytes +.br +tape address 2 bytes +.br +unused 20 bytes +.br +check sum 2 bytes +.sp +.in -3 +The path name entry is the path name of the +file when put on the tape. +If the pathname starts with a zero word, +the entry is empty. +It is at most 32 bytes long and ends in a null byte. +Mode, uid, size and time modified +are the same as described under i-nodes (see file system (V)) +The tape address is the tape block number of the start of +the contents of the file. +Every file +starts on a block boundary. +The file occupies (size+511)/512 blocks +of continuous tape. +The checksum entry has a value such that +the sum of the 32 words of the directory entry is zero. +.sp +Blocks 25 (resp. 147) on are available for file storage. +.sp +A fake entry (see mt(I), tap(I)) +has a size of zero. +.sp +.ti 0 +SEE ALSO filesystem(V), mt(I), tap(I) |