MEAN-18 UnProtect   by Independent (IND)

1/22/88 ********************* * * * MEAN-18 UnProtect * * For EGA Version * * * ********************* THIS PATCH IS INTENDED TO BE USED TO ALLOW YOU TO MAKE A BACKUP COPY OF YOUR SYSTEM DISK TO BE USED IN CASE YOU DAMAGE YOUR ORIGINAL DISKETTE. This patch will also allow you to run the program from your hard drive without the need to have your system disk in drive A:. The patch works by eliminating the code that tests for known bad sectors on the original diskette to see if it is the genuine article or an illegal copy. The code begins with an INT 13 (CD 13 HEX), a DOS BIOS disk service routine followed a few bytes later by another INT 13 instruction. The program then checks the returned value for the bit configuration that signifies the bad sectors and, if all is as expected, continues on with program execution. The code that needs to be patched is in the GOLF.EXE file and in the ARCH.EXE file. It is identical in both files and lies near the end of each file. In the following steps, you'll locate the start of the test code and patch it by replacing it with NOP instructions (HEX 90). The method described uses the DOS DEBUG utility but Norton's Utility (NU) works too. Copy all of the files from the MEAN-18 disk onto a fresh floppy using the DOS COPY command and place your original diskette out of harm's way. Assuming DEBUG is in the A: drive and the floppy containing the files to be unlocked is in the B: drive , proceed as follows: A:> DEBUG B:GOLF.EXE (Loads the file GOLF.EXE into memory and displays the "-" DEBUG prompt. Search for the beginning of the code to be patched by typing:) - S CS:100 FFFF CD 13 (Searches the file for the two byte INT 13 instruction. If all goes well, two addresses should appear on the screen. XXXX:019C XXXX:01A8 ♀ XXXX indicates that the numbers preceeding the ":" vary from system to system but the numbers following the ":" are the same on all systems. The next step is to use the "U" command as indicated to un-assemble a few bytes in order to verify your position in the file) - U CS:019C (Un-assembles 32 bytes of code. Verify the following sequence of instructions: INT 13 JB 01E9 MOV AL,[BX+01FF] PUSH AX MOV AX,0201 INT 13 POP AX JB 01E9 CMP AL,F7 JNZ 01B5 (These are the instructions you'll be patching out in the following step) - A CS:019C (This command assembles the new instructions you enter at the keyboard into the addresses shown. Beginning at CS:019C, and for the next 21 bytes, ending with and including CS:01B0, enter the no op command "NOP" followed by a <return> or <enter>. Just hit <enter> at address XXXX:01B1 to end the assemble command.) XXXX:019C NOP <enter> XXXX:019D NOP <enter> . . . XXXX:01AE NOP <enter> XXXX:01AF NOP <enter> XXXX:01B0 NOP <enter> XXXX:01B1 <enter> - D CS:019C (Do a HEX dump and verify that bytes 019C through 01B0 have been set to 90 HEX. If they have, write the patched file to the disk as follows) ♀ - W (Writes the patched file back to the disk where it can be run by typing GOLF just as before but now, it can be run from any drive, including the hard drive) - Q (Quit. Exit back to DOS. This command can be executed at any "-" DEBUG prompt if you get lost. No modification will be made to the file on the disk until you issue the "W" command. The process is the same for the ARCH.EXE file but because it is a different length, the segment address, (XXXX part of the address), will be different. You should find the first INT 13 instruction at address XXXX:019C and the second one at XXXX:01A8 as before. You will again be patching 21 bytes and you will start with 019C and end with 01B0 as before. After doing the HEX dump starting at address 019C, you again write the file back to the disk with a "W" command then "Q" uit. Norton's utilities can also be used to make this patch. Begin by searcing the GOLF.EXE or ARCH.EXE files for the two byte combination CD 13 (remember to enter these as HEX bytes). Once located, change the 21 bytes, starting with the first "CD" byte, to 90 (a NOP instruction). As a check that you are in the right place, the byte sequence in both files is CD 13 72 49 8A 87 FF 01 50 B8 01 02 CD 13 58 72 3C 3C F7 75 04. After modifying the bytes, write the modified file back to the disk. It can then be run from any drive. Remember to work only with a copy of your system disk. DEBUG and NORTON's are great tools but they can really mess you up if you're not careful. Remember too, that pirating software is just plain stealing. This patch is for convenience, not proliferation of pirated copies. Use it in the spirit it was intended. →♀