The PDP-11 Volume Preservation Utility (PRESRV) is a standalone program used to create copies of volumes in three formats: Files-11 Logical tape Image The general form of a PRESRV command line is: outdev:[label][/switches]=indev:[label][/switches] where: outdev are the devices on which the output and input indev volumes are mounted. Their form is ddn:, where dd is the device name (two ASCII letters) and n is the octal unit number. N is always 0 or 1 unless the /UNIT switch is used. label a label for the file when a volume is written as a logical tape. It is used to identify files on logical tapes. The label can consist of up to nine alphanumeric characters. A label must be specified when the output is a logical tape. It is optional for input. switches one or more of the following optional switches Category Switch Function List /HE Causes a summary of PRESRV commands, switches, and defaults to be printed on the terminal /LI Causes a list of all files on a logical tape volume to be printed on the terminal. Format /FI On input, indicates Files-11 format for reading or writing a disk volume. On Output, overrides the /TP default or implied /IM. /IM Indicates image mode, transfer all physical blocks of an input disk. Never used with magtape. /TP Indicates a logical tape format volume (which overrides the default image mode when device types are identical). /BL:n Specifies a blocking factor for I/O operations. Octal is assumed; decimal is indicated by a trailing decimal point. Administrative /ER Indicates that the PRESRV operation is to be terminate if an I/O error occurs. /FO Indicates that the output disk pack is to be formatted before use /RW Causes a cassette or magtape volume (either input or output) to be rewound at completion of PRESRV operation. Note that PRESRV rewinds only the last volume of a multi- volume set when it is completely finished. Intermediate volumes must be rewound at the user. /VE Causes the output volume to be verified after it is written. Magnetic tapes /20 Indicates a recording density of 200 bpi for 7-track magtape. Image transfers only. /55 Indicates a recording density of 556 bpi for 7-track magtape. Image transfers only. /80 Indicates a recording density of 800 bpi for 7-track magtape. Image transfers only. /PE Indicates a recording density of 1600 bpi (phase encoded). Can be used only for TU16/TE16/TU45/TU77 tape drives. Standalone /CSR=n Changes the control status register for a device type /UNIT=n Sets the physical unit number of either PRESRV unit 0 or 1 to a value from 2 to 7. /VEC=n Changes the interrupt vector address for a device type. /TM02=n Sets the unit number of the TM02 formatter on an RH controller for a specific TU16 magtape unit. Note that /CSR, /UNIT, /VEC, and /TM02 can all be specified in the same command line. /TIM=mm/mm/dd/yy hh:mm[:ss] Specifies the correct time of day to the system. All values are implied decimal. /BO Causes PRESRV to "hardware" bootstrap the system from the specified device.