Dskpat (DPU) is a disk patch utility for RSX/VMS.  It is
entirely written in FORTRAN IV PLUS, but could be made to run under
FORTRAN IV by removing the INCLUDE and PARAMETER statements.  Since it
is still under development on our own time there may be problems or
features that have been left out that will be in the utility in the
future.  The command syntax is less than elegant but is functional
and fairly concise.  No guarantees are made as to its realiability or
usability, but the authors are interested in comments and additions.

					Todd Little and Steve Freyder
					Systems Analysts
					Science Applications, Inc.
					4030 Sorrento Valley Blvd.
					San Diego, CA  92121
					(714) 452-1720




COMMAND SUMMARY:

O[PEN] filespec		Opens the specified file for virtual i/o
O[PEN] device		Opens the specified device for logical i/o
RV blocknum		Reads the specified virtual block from the currently
			open file.
RL blocknum		Reads the specified logical block from the currently
			open device.
WL blocknum		Writes the buffer back to the logical block
			specified by blocknum on the currently open
			disk.
RV blocknum		Reads the specified virtual block number from
			the currently open file into the buffer.
WV blocknum		Writes the buffer to the virtual block number
			specified in the currently open file.
REW			Rewrites the last read block, i.e. either a
			WV or WL to the last block number specified.
CH F V			Verifies that the buffer contains a proper
			checksum for a file header.
CH F W			Writes a proper checksum to the buffer for a
			file header.
CH H V			Verifies both checksums in the buffer for a home
			block style checksum.
CH H W			Writes both home block style checksums to the buffer.

offset/contents		Allows the specified location in the buffer to be
			modified by placing the contents into offset.
offset			Lists the next octal 100 locations on the terminal
			in octal, ASCII, and RAD50.


	Block numbers can be specified as either L or as H,L where L is
the lower 16 bits, and H is the upper 8 bits.  Numeric quantities can
be entered in either octal (default), decimal (trailing period), ASCII
(prefixed with "), RAD50 (prefixed with %).


	Please note, this documentation was written while the SIG tape
was being generated and may not be totally accurate.  The sources are
fairly readable, and should be simple to change.  One last thing, there
are includes which reference specific UIC's, these will need to be changed.