File:  DIFF/DOC
Subj:  Description and Instructions for DIFF/CMD
Ver:   2.0
DOS:   TRSDOS/LS-DOS 6.2, 6.3

Description:

DIFF/CMD is a Share Ware utility program for TRS/LS-DOS 6.x designed
to show differences between two files, most expectedly between two 
versions of the same binary (/CMD, /CIM, /SYS, etc) files.  DIFF is 
very useful to the assembly programmer who patches files originally 
with a "ZAP" utility, then wishes to develop patch code to allow 
him to share his work with others in an common manner.  

DIFF will not, as many mainframe DIFFERENCES utilities, attempt to 
"catch up" on lines omitted from one version, since it is intended 
primarily for binary files where absolute addresses will all be 
changed after inserted source code.  It will allow the user to 
compare files of different sizes, but the output will stop as soon 
as the shorter file is exhausted.  Version 3, when released, will
support line-by-line comparisons of ASCII text files.  Version 3 will
not be available in an un-registered version that supports text files!
If this is needed to you, register your current version now!

Instructions:

DIFF is a very simple program to use -- it will provide you with a 
brief format for entering parameters if you enter only the command 
DIFF with no useful information following.  (The full featured 
version would allow you to enter filespecs at prompts.)

The format for running DIFF is as shown here.  At the xxxDOS ready 
level, enter:

                         DIFF File1 File2

where File1 is the name of the first file to compare, and File2 is 
the name of the second.  File1 and File2 must both conform to the 
standard file specification rules.  If you omit an extension (/abc) 
on File2, DIFF will use the same one as File1's.  If you neglect to 
enter File2, DIFF will show you the correct format and return you 
to the DOS ready.  An example of the command to compare two files 
is:

             DIFF SYS6/SYS.LSIDOS:0 SYS6/SYS.LSIDOS:1

Miscellaneous:

DIFF will trap all errors during execution, and route them to the 
standard error device (usually the video).  Errors occurring on the 
video device may not be reported properly, but should not hang the 
system.

DIFF is smart enough to open the input files for read access only.  
This guarantees you that your input files will not be corrupted by 
DIFF, unless you route the output to one of the input files -- 
THAT'S YOUR OWN FAULT IF YOU TRY IT!

DIFF may be aborted at any time by pressing the <BREAK> key.  The 
output may be paused by pressing the "@" key (shifted or unshifted) 
or single-stepped using the space bar.  To resume normal operation 
after pausing, press the <ENTER> key.

Features Unique to the Registered Version:

The optional parameters for the full-featured version of DIFF will 
allow you to direct output to either video or printer, and 
optionally to a file. Output may be directed to either the printer 
OR the video (not BOTH or NEITHER).  Output defaults to only video, 
but will go the the printer if you enter (PRT) at the end of the 
command line.  Note that P is a valid abbreviation for PRT.

Output may also be directed to a text file by using the FILE 
parameter, which may be used in two forms.  You may enter (FILE) at 
the end of your command line, in which case output will go to a 
file by the name of File1, with the extension /DIF.  If you entered 
DIFF MYFILE/CIM OLDFILE (FILE), the output would go the the screen 
(since you didn't tell it to go to the printer) and to MYFILE/DIF.  
You may also specify the name of the file to receive output by 
using (FILE="MYOLD/TXT").  If you do not give an extension to the 
output file, it will default to "/DIF".  Note that F is a valid 
abbreviation for FILE.

An example of the full command line is:

                DIFF BETA/CMD GAMMA (P,F="DELTABC")

In this example, the files being compared are BETA/CMD and 
GAMMA/CMD, with the output going to both the printer and to a file 
named DELTABC/DIF.

It should be noted that the output differs slightly when directed 
to the printer.  The difference will also be sent to the file, 
should you have directed it to both printer and file.  The 
difference is minor -- a message appears at the beginning which 
tells that the output was generated by DIFF.

There are also differences in the output when differences are 
discovered between the files.  The best way to understand what 
happens is to play with it a little, comparing *small* files of 
different sizes, with many and few differences, with output to 
different places.

Registration:

To register your copy of DIFF (and any additional Share Ware from 
Software Specialties), send:

     1) $10 (US funds only: check or money order),
     2) preferred diskette format (specify DOS version, disk size, 
        sides, and density),
     3) your name,
     4) address,
     5) ZIP (necessary!),
     6) daytime phone (in case of problems),
     7) name and (if possible) registration number of person you
        received your unregistered copy from (If a BBS, please state 
        which one, with phone number of BBS and SYSOP name)

to:

     Software Specialties
     220 Sixth Street
     Colonial Beach, VA  22443 USA

You will receive a diskette with the most recent registered version(s)
and be placed on the mailing list for new products.  NOTE:  The registered
version has several more capabilities than the unregistered version,
and there are other differences in the program.  You won't get updates
unless you register it!

Share Ware -- What is it?

Share Ware is an emerging method of software distribution which uses
the most effective advertising method to spread the news of the 
products -- word of mouth.  With Share Ware, a person receives a
(usually limited capabilities version) software package with adequate
documentation.  If the user likes the package or wishes to upgrade it,
he sends the author/publisher a fee, and receives the latest & greatest
version of the package with full documentation and complete user support
services.  The user is free to copy and distribute the UNREGISTERED
(limited capabilities) copy of the software to his friends, etc, as long
as he makes no charges for the product.  This is similar to public domain,
but the software IS STILL COPYRIGHTED and pirates may be punished under 
Federal law.

With Share Ware, the user gets a bargain, since he did not pay to receive
the initial version, and the fee to upgrade is usually nominal, often far
less than equivalent "name-brand" packages.  The smart user will register
his software with the author since he is then provided with product news,
support services, and a better product, and it won't cost him nearly as
much as the alternatives might.
