Preliminary DUD README doc
		March 1, 1991

DUD is a Disk Uploading/Downloading utility.  It lets you upload/download
entire 5.25" Apple // disks without paying attention to the file format, as
long as the disk uses 16-sector tracks with standard encoding.

DUD reads the entire disk, and splits it up into files.  Each file contains
a number of tracks from the disk (set by the variable NT in DUD).  Run-length
compression is used to replace, say, $A1 zeros by the sequence $00 A1 3C
($3C is a special marker which indicates a run-length encoding coming up -
the compressed file is read in backwards).
You then upload these files to a bulletin board.  Someone who wants to download
your disk downloads the files onto 1 or more disks, and then runs DUD on those
files.

DUD runs ONLY UNDER DOS 3.3!  It can, of course, transfer disks written
under ProDOS or CP/M or Pascal (though not DOS 3.2 disks).  You can run
DUD with only 1 drive, or with 2.

If you modify DUD, be careful to leave space between the end of the Applesoft
program and the binary, between the end of the binary and the buffer for disk
sectors, and the end of the disk buffer and Applesoft string storage space.
The Applesoft program DUD is designed to read the address of the buffer from
the binary, as well as the binary's starting location from locations $AA73, 72.

I am aware of a more professional-looking product called "Disk Rigger",
which gets slightly better compression on disks with hi-res pictures, as it
also compresses runs of cycles of length 2 bytes.  However, DUD has the
advantage that it works, whereas Disk Rigger (at least my copy) often does not.

Files:
	dud.txt		Text file of the Applesoft program DUD.
			Put it on an Apple disk, then type
				NEW
				EXEC DUD.TXT
				SAVE DUD
	dudobj		Binary file BLOADed by DUD.
	dudobj.01	BINSCII'd dudobj.
	dudobj.ed.txt	Text file of the S-C Macro Assembler source code				for dudobj.  I think to load it in from the assembler
			you type AUTO, then backspace to the first column
			and type EXEC DUDOBJ.ED.TXT.  But I could be wrong.

DUD is copyrighted 1991 by

Phil Goetz
4023 Huckleberry Row
Ellicott City, MD 21043
goetz@cs.buffalo.EDU

Enjoy!