tcopy —
copy and/or verify mag tapes
  
    | tcopy | [ -cvx] [-smaxblk] [src
      [dest]] | 
tcopy is designed to copy magnetic tapes. The only
  assumption made about the tape is that there are two tape marks at the end.
  tcopy with only a source tape
  (/dev/rst0 by default) specified will print information
  about the sizes of records and tape files. If a destination is specified a
  copy will be made of the source tape. The blocking on the destination tape
  will be identical to that used on the source tape. Copying a tape will yield
  the same output as if just printing the sizes.
Options:
  - -c
- Copy src to dest and then
      verify that the two tapes are identical.
- -smaxblk
- Specify a maximum block size, maxblk.
- -v
- Given the two tapes, src and
      dest verify that they are identical.
- -x
- Output all informational messages to the standard error. This option is
      useful when dest is
      /dev/stdout.
Thetcopy command appeared in
  4.3BSD.