TPC - Fast GENERAL Tape Copy
		============================

			Users' Guide
			============

 This  program  will copy a complete DOS-11 or virtually ANY format magtape
 to a Files-11 disk and  store it there in a special image mode, from which it
 can create one or more copies of the tape (must faster than FLX or any other
 known utility ever could).   BIGTPC is able to do this, and also will handle
 any block size on tape up to 4200. bytes (big enough for BRU tapes). By going
 from 4 to 3 buffers for tape and smaller numbers of disk blocks per read/write
 still larger tape block sizes could be handled. Also, several additional
 switches are supported.

 The command format is:-

	TPC>Output-filespec=Input-filespec<switches>

 where one  of the 'filespecs' must be a magtape device (e.g. MT:) and
       the other the name of an image file on disk.

 Legal switches are:-

       /BL:nnnn - Specifies  an  initial  allocation specification for
                  the image file if a disk is the output device.
       /SA:nnnn - Specifies  a  secondary allocation specification for
                  the image file if a disk is the output device.
       /CO      - Specifies that the disk file is to be contiguous
       /HD      - Indicates High Density (1600 BPI) tape is to be
		  written. (For TE16, tape is read at the proper density
		  automatically.) This permits a container file from one
		  density to be written out in another.
       /HE	- Displays HELP containing this list of switches and comments
       /NR	- Specifies NO positioning of the tape prior to the
		  start of copying. This will allow TPC to merge
		  several backup collections on a single output tape
		  if used with care. Since at the end of a copy
		  TPC will be positioned after the 2nd of 2 EOF records,
		  another utility (see [312,315] for one) must be used tp
		  backspace the tape 1 record before using TPC with this
		  switch.
       /ER	- Specifies that TPC will ignore errors on tape. This
		  specifically means that all errors except EOT/EOV/EOF
		  will be ignored. This is quite useful for recovering
		  data from tapes which are old and full of errors, or for
		  writing an output to a tape with bad spots (though
		  it won't cure bad spots and this method of writing
		  anyway is not necessarily a good idea...).
       /AN	- ANSI format tape, uses EOV1 & EOV2 to detect the real
		  end-of-tape, thus avoiding problems with ANSI tapes with
		  zero-length files which have 2 consecutive EOT's.
       /EB	- EBCDIC labels (requires /AN switch)
       /SC:NNNN	- Sets tape characteristics to NNNN (octal)


 So that, for instance,

		TPC>BACKUP=MT:

 will create the file BACKUP (.DOS by default) from the magtape on MT:, and

		TPC>MT:=BACKUP

 would then create an exact copy of the original magtape onto the tape
 now mounted on MT:.

 Note that TPC will only handle one tape at a time and cannot handle
 block sizes of greater than 4200 bytes without edit and rebuild. If
 the tapes are FLX format tapes, however, the TPCDIR program (S81-[312,315])
 may be used to list directories or extract copies of files in the
 container file, though in a fairly cumbersone way. Otherwise, BIGTPC
 acts as a format-independent tape copy to EOT (signalled by 2 consecutive
 EOFs) or EOV (signalled by the /AN switch and EOV1 + EOV2).

 TPC can report the following errors:-

 1.  TPC - DISK I/O ERROR.  CODE = n

     TPC encountered an error while reading from/writing to the disk.

 2.  TPC - MAGTAPE I/O ERROR.  CODE = n

     TPC encountered an error while reading from/writing to the magtape.

 3.  TPC - COMMAND LINE INPUT ERROR

     TPC encountered an error in reading the commandline.

 4.  TPC - COMMAND LINE SYNTAX ERROR

     TPC encountered an error when trying to parse the command line.

 5.  TPC - INVALID SWITCH

     The  commandline contained a switch that TPC could not recognise,
     or a file specification that it could not parse.

 6.  TPC - OPEN ERROR ON OUTPUT FILE

     A file was specified as output, but TPC encountered an error when
     it tried to open it.

 7.  TPC - OPEN ERROR ON INPUT FILE

     A  file was specified as input, but TPC encountered an error when
     it tried to open it.

 8.  TPC - SPECIFY 1 FILE & 1 MAGTAPE DEVICE

     The commandline either specified magtape as both input and output
     device, or a disk file as both input and output device.

   TPC tends to crash when it has an allocation failure while reading
 tape to disk.