177 lines
7.7 KiB
Plaintext
177 lines
7.7 KiB
Plaintext
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Unprotect for all Sierra Games using the version 3.0 SIERRA.COM game
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loader and the AGI (Adventure Game Interpreter).
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This text written
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July 11, 1988
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Sierra-On-Line Software utilizes a copy protection scheme which, upon
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the execution of the game loader (usually SIERRA.COM), loads some key data
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from a specially formatted track. Normal DOS copy and diskcopy commands
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cannot copy this specially formatted track (usually track 6). Only image
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hardware copy devices such as the "OPTION BOARD" can copy the specially
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formatted track properly - and even this will not allow stand-alone hard
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disk usage.
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This unprotect is accomplished by running the program to the point where
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it loads the key data, and then copying the key data into the loader. Then
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the loader is further modified by jumping around the call to the "opening
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original disk" request screens. The last step is to change the bx and cx
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registers to allow for the inclusion of the key data in the loader.
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There are three things to determine before you can start the unprotect.
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The first is to verify that your game contains the version 3.0 game loader
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(usually the file SIERRA.COM) and the file "AGI". This applies to about 90%
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of all Sierra games. The others contain a slightly modified version 3.0
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game loader and the file MAIN. This unprotect does not apply to Sierra
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games that contain the file "MAIN". Some games which use the "MAIN" file
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are: 3-D Helicopter, Thexder and a few others. Check this BBS for a
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different unprotect for Sierra games using the "MAIN" file.
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Run a directory on your Sierra game disk 1 to verify that is does contain
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the files "SIERRA.COM" and "AGI".
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The next step is to determine which version of the 3.0 game loader
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(SIERRA.COM) your game has. Yes, there are two different versions of the
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3.0 version game loader. In the code of the SIERRA.COM file is listed
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either the date 1985 or 1987 - the 1985 being one version and the 1987
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being another version. You must run a debug operation as follows to
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determine your version of the game loader:
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Arrange your configuration so that SIERRA.COM
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and DEBUG.EXE are on the same disk, directory
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or path.
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DEBUG SIERRA.COM <return>
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-d 100 <return>
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Some text will now appear to the right of your screen, somewhere
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containing "LOADER v.3 Copyright Sierra On-Line, Inc. 198?". Note the
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year appearing in this text. Now you can quit debug by typing a "q" at
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the "-" prompt. The unprotect differs for the 1985 and 1987 versions,
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so, if your version is the 1985 version, refer to the file SIERRA85.UNP
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contained in this package. Likewise, if your version is the 1987 version,
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refer to the file SIERRA87.UNP contained in this package.
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Please read the file READTHIS.1ST before proceeding to read this file.
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Unprotect for all Sierra Games using the version 3.0 SIERRA.COM game
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loader and the AGI (Adventure Game Interpreter). THE FOLLOWING PROCESS
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APPLIES TO THE 1985 version of the 3.0 version SIERRA.COM game loader!
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Make a copy of your original game disk 1 using the dos copy *.* command.
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But don't put away your factory original game disk yet, you will need
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it during the unprotect.
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Arrange your configuration so that SIERRA.COM and DEBUG.EXE are on the
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same disk, directory or path.
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Using THE COPY of the game disk 1, start as follows:
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DEBUG SIERRA.COM <return>
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-r <return>
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(Now a listing of all the registers will appear on the screen. Write down
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the value of the BX and CX registers for later use)
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-g 0390 <return>
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(The program will now run with a breakpoint set after the call to the
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protection key data load. Follow the instructions on the screen, including
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the prompt to insert your original disk (write protect it to be safe). The
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key data from the specially formatted track will be loaded into memory.
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When the program breaks back to debug (the registers will be listed again),
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be sure you have the COPY you made of your original disk in the disk drive.)
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-rbx <return>
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BX XXXX
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: <-type in here the value of BX register that
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you were instructed to write down in step one.
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<return>
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-rcx <return>
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CX XXXX
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: <-type in here the value of CX register that
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you were instructed to write down in step one.
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<return>
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-e 038D <return>
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xxxx:03C1 E8.90 <space> 0E.90 <space> 04.90 <return>
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(In the above line you have inserted NO-OP's (90's) to jump around the
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protection check and opening screen calls)
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-w <return> (this will write back to disk the unprotected
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game loader)
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Writing xxxx bytes
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-q <return> (quits debug)
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This completes the Sierra game 1985 version 3.0 game loader unprotect. Use
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this unprotect to allow proper hard disk usage or to make an archival backup
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copy. Please do not promote theft by using this procedure to distribute
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unauthorized copies.
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Bart Montgomery
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Atlanta PCUG BBS
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(404) 433-0062
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Please read the file READTHIS.1ST before proceeding to read this file.
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Unprotect for all Sierra Games using the version 3.0 SIERRA.COM game
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loader and the AGI (Adventure Game Interpreter). THE FOLLOWING PROCESS
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APPLIES TO THE 1987 version of the 3.0 version SIERRA.COM game loader!
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Make a copy of your original game disk 1 using the dos copy *.* command.
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But don't put away your factory original game disk yet, you will need
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it during the unprotect.
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Arrange your configuration so that SIERRA.COM and DEBUG.EXE are on the
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same disk, directory or path.
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Using THE COPY of the game disk 1, start as follows:
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DEBUG SIERRA.COM <return>
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-r <return>
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(Now a listing of all the registers will appear on the screen. Write down
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the value of the BX and CX registers for later use)
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-g 03C4 <return>
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(The program will now run with a breakpoint set after the call to the
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protection key data load. Follow the instructions on the screen, including
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the prompt to insert your original disk (write protect it to be safe). The
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key data from the specially formatted track will be loaded into memory.
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When the program breaks back to debug (the registers will be listed again),
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be sure you have the COPY you made of your original disk in the disk drive.)
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-rbx <return>
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BX XXXX
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: <-type in here the value of BX register that
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you were instructed to write down in step one.
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<return>
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-rcx <return>
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CX XXXX
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: <-type in here the value of CX register that
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you were instructed to write down in step one.
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<return>
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-e 03C1 <return>
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xxxx:03C1 E8.90 <space> 2E.90 <space> 04.90 <return>
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(In the above line you have inserted NO-OP's (90's) to jump around the
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protection check and opening screen calls)
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-w <return> (this will write back to disk the unprotected
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game loader)
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Writing xxxx bytes
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-q <return> (quits debug)
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This completes the Sierra game 1987 version 3.0 game loader unprotect. Use
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this unprotect to allow proper hard disk usage or to make an archival backup
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|||
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copy. Please do not promote theft by using this procedure to distribute
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|||
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unauthorized copies.
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Bart Montgomery
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Atlanta PCUG BBS
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(404) 433-0062
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