UNPBASIC.DOC

UNPBASIC.COM
Unprotect Basic Version 1.10  12/21/1990  John Thomason
 
Usage: UNPBASIC  filename1  [filename2]
  filename1 = protected Basic file
  filename2 = unprotected Basic file (default FIL.BAS)
 
Entering UNPBASIC with no filename will display the above information.
 
This utility removes the "protection" from GW-BASIC (R) files saved
with the "P" option.  File size must be no larger than about 62K.
 
The ability to unprotect Basic source files is a useful one because
the Basic interpreter will not allow a protected file to be listed,
printed, or modified.  Basic programmers who've misplaced their
unprotected version of a program can use this utility to restore
the source code.  Those who download protected Basic files from BBSs
can use UNPBASIC to reveal potentially harmful code.
 
This utility is simpler than other available unprotect schemes because
one needs only the UNPBASIC.COM file.  Other routines call for the
use of the Basic interpreter and Debug, along with a working knowledge
of system-specific memory allocation.  Still other schemes employ a
POKE or BLOAD after loading the protected program into the interpreter,
which may or may not be allowed, depending on the interpreter.
 
The program may be duplicated and used without restriction.
Encryption method hacked by John Thomason, GEMail SWAN12.
GW-BASIC is a registered trademark of the Microsoft Corporation.
 
 
Changes from version 1.00:
1. file length shortened
2. EOF delimiter changed from FF1Ah to 001Ah for compatibility with
   later versions of GW-BASIC.