TP(5) File Formats Manual TP(5)
tp - DEC/mag tape formats
The command tp dumps files to and extracts files from DECtape and mag-
tape. The formats of these tapes are the same except that magtapes
have larger directories.
Block zero contains a copy of a stand-alone bootstrap program. See
Blocks 1 through 24 for DECtape (1 through 62 for magtape) contain a
directory of the tape. There are 192 (resp. 496) entries in the direc-
tory; 8 entries per block; 64 bytes per entry. Each entry has the fol-
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, gid, size and
time modified are the same as described under i-nodes (see file system
filsys(5)). 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.
Blocks above 25 (resp. 63) are available for file storage.
A fake entry has a size of zero.
The pathname, uid, gid, and size fields are too small.