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GRAFWRTR.TXT
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1986-03-16
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3KB
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91 lines
HOW TO UNPROTECT "GRAPHWRITER" v 4.3 by Graphic Communications
First, make a copy of the Graphwriter "System Batch" disk. NEVER
mess around with your original distribution disk!
The copy protection for Graphwriter is contained in the file
GW10.OLY. We will use DEBUG on this file.
Debug GW10.OLY
-s cs:000 l ffff 25 00 ff [search for beginning of
test sequence]
xxxx:1D67
-u 1d67 l 40
xxxx:1D67 2500FF AND AX,FF00
xxxx:1D6A 0BC0 OR AX,AX
xxxx:1D6C 7531 JNZ 1D9F <--NOTE This Jump
xxxx:1D6E 80BE00FE47 CMP BYTE PTR [BP+FE00],47
xxxx:1D73 752A JNZ 1D9F
xxxx:1D75 80BE01FE57 CMP BYTE PTR [BP+FE01],57
xxxx:1D7A 7523 JNZ 1D9F
xxxx:1D7C 80BE02FE04 CMP BYTE PTR [BP+FE02],04
xxxx:1D81 751C JNZ 1D9F
xxxx:1D83 80BE03FE01 CMP BYTE PTR [BP+FE03],01
xxxx:1D88 7515 JNZ 1D9F
xxxx:1D8A 80BE04FE52 CMP BYTE PTR [BP+FE04],52
xxxx:1D8F 750E JNZ 1D9F
xxxx:1D91 80BE05FE42 CMP BYTE PTR [BP+FE05],42
xxxx:1D96 7507 JNZ 1D9F
xxxx:1D98 80BE06FE4A CMP BYTE PTR [BP+FE06],4A
xxxx:1D9D 7457 JZ 1DF6 <--NOTE this
address!
The last jump address in the sequence is the place where Graphwriter goes once
it has satisfied itself that it has a valid original in drive A:. We will
just persuade it to go there a little bit early:
-a 1d6c
xxxx:1D6C JMP 1DF6 <--assemble a new
xxxx:xxxx <cr> ;to end assembly jump at the first
jump location!
So GW never gets to test for the goodness of the diskette...
Next, search for a diskette interrupt:
-s cs:0 l ffff cd 13
xxxx:1E19
-u 1e10
xxxx:1E10 8A460E MOV AL,[BP+0E]
xxxx:1E13 8A6610 MOV AH,[BP+10]
xxxx:1E16 8B5E12 MOV BX,[BP+12]
xxxx:1E19 CD13 INT 13 <--Here it is!
xxxx:1E1B 8BF0 MOV SI,AX
xxxx:1E1D 8BC6 MOV AX,SI
xxxx:1E1F 5E POP SI
xxxx:1E20 5D POP BP
xxxx:1E21 C3 RET
xxxx:1E22 55 PUSH BP
xxxx:1E23 56 PUSH SI
xxxx:1E24 8BEC MOV BP,SP
xxxx:1E26 81EC0400 SUB SP,0004
xxxx:1E2A C746FC0100 MOV WORD PTR [BP-04],0001
xxxx:1E2F EB03 JMP 1E34
Now, let's get rid of the nasty thing:
-a 1E19
xxxx:1E19 nop
xxxx:1E1A nop
xxxx:1E1B <cr> ;to break out of assembly
Now GW won't even bother to check drive A: at all!
-w
Writing 693A bytes
-q
Graphwriter has been unprotected. It may now be freely copied, run from a hard
or ram disk, etc. NOTE: you may have to run the hard disk install or use an
ASSIGN a=c statement in order to keep Graphwriter from looking for overlays on
drive A:...
LET THERE BE SOFTWARE!
<Gosh, this is fun!>