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Text File  |  1985-05-25  |  4KB  |  76 lines
  1.  
  2. The following is a method to unprotect MultiLink ver 3.01 to allow
  3. booting directly from a hard disk without the need to insert the
  4. MultiLink distribution diskette.
  5.  
  6.   ENTER                          COMMENTS
  7. ----------------               ------------------------------------
  8. C>copy mlink.com mlink.bak     Make a backup first!
  9. C>debug mlink.com              Start the debug session.
  10. -u 4269                        Unassemble from address 4269; you should
  11.                                see the following. If you don't, enter
  12.                                'q' to quit the debug session.
  13.  
  14.                    xxxx:4269 8036A14132    XOR     BYTE PTR [41A1],32
  15.                    xxxx:426E B90329        MOV     CX,2903
  16.                    xxxx:4271 E81E00        CALL    4292    <-+
  17.                    xxxx:4274 732D          JNB     42A3      |_ need to
  18.                    xxxx:4276 B90829        MOV     CX,2908   |  change
  19.                    xxxx:4279 E81600        CALL    4292    <-+
  20.                    xxxx:427C 7325          JNB     42A3
  21.                    xxxx:427E FE0E602F      DEC     BYTE PTR [2F60]
  22.                    xxxx:4282 7FEA          JG      426E
  23.                    xxxx:4284 FE065F2F      INC     BYTE PTR [2F5F]
  24.                    xxxx:4288 803E5F2F01    CMP     BYTE PTR [2F5F],01
  25.  
  26. -e 4271 f8 90 90               Change CALL 4292 to CLC, NOP, NOP
  27. -e 4279 f8 90 90               Change CALL 4292 to CLC, NOP, NOP
  28.  
  29. -u 42a0                        Unassemble from address 42a0.
  30.  
  31.                    xxxx:42A0 CD21          INT     21
  32.                    xxxx:42A2 C3            RET
  33.                    xxxx:42A3 A17333        MOV     AX,[3373]
  34.                    xxxx:42A6 39067038      CMP     [3870],AX  <- need to
  35.                    xxxx:42AA 75D8          JNZ     4284       <- change --+
  36.                    xxxx:42AC 8036A14132    XOR     BYTE PTR [41A1],32 <---+
  37.                    xxxx:42B1 EB02          JMP     42B5
  38.                    xxxx:42B3 51            PUSH    CX
  39.                    xxxx:42B4 06            PUSH    ES
  40.                    xxxx:42B5 B8E8FF        MOV     AX,FFE8
  41.                    xxxx:42B8 50            PUSH    AX
  42.                    xxxx:42B9 8B365600      MOV     SI,[0056]
  43.                    xxxx:42BD E871EC        CALL    2F31
  44.  
  45. -e 42a6 90 90 90 90 90 90 90 90 90 90 90
  46.                                Change CMP [3870],AX, JNZ 4284, & XOR
  47.                                BYTE PTR [41A1],32 to all NOPs (11 bytes)
  48.  
  49. -u 4370                        Unassemble from address 4370.
  50.  
  51.                    xxxx:4370 F8            CLC
  52.                    xxxx:4371 3B17          CMP     DX,[BX]
  53.                    xxxx:4373 740B          JZ      4380
  54.                    xxxx:4375 8D161638      LEA     DX,[3816]
  55.                    xxxx:4379 B409          MOV     AH,09
  56.                    xxxx:437B CD21          INT     21
  57.                    xxxx:437D FA            CLI             <-- need to
  58.                    xxxx:437E EBFE          JMP     437E    <-- change
  59.                    xxxx:4380 C606DB0DFF    MOV     BYTE PTR [0DDB],FF
  60.                    xxxx:4385 33C0          XOR     AX,AX
  61.                    xxxx:4387 803E9C0D00    CMP     BYTE PTR [0D9C],00
  62.                    xxxx:438C 740B          JZ      4399
  63.                    xxxx:438E B80031        MOV     AX,3100
  64.  
  65. -e 437d 90 90 90               Change CLI, JMP 437E, to NOP, NOP, NOP
  66.  
  67. -e 3916 20 20 20               Also change "ZZZ" to blank-blank-blank.
  68.  
  69. -w                             Write out the changes.
  70.  
  71. -q                             Quit the debug session.
  72.  
  73.  
  74. *End of MLINK301.UNP*
  75.  
  76.