code segment
assume cs:code,ds:code
org 100h
begin:jmp init
int9 dd ?
ddxx db 0
mess db 'now start with $'
handle dw ?
buffer db56*3 dup (0)
path db 'pic*.',0
dta db5 dup(?)

new_int proc far
sti
push ax
push es
xor ax,ax
mov es,ax
in al,60h
test al,80h
jnz exit1
test byte ptr es:[0417h],100b
jz exit1
cmp al,59
jnz exit1
push ax
push bx
push cx
push dx
push bp
push di
push si
push ds
push cs
pop ds
in al,61h
push ax
or al,80h
out1h,al
pop ax
out1h,al
mov al,20h
out0h,al
call savescr

exit:
pop ds
pop si
pop di
pop bp
pop dx
pop cx
pop bx
pop ax

exit1:
pop es
pop ax
jmp cs:int9
new_int endp
savescr proc near
push cs
pop ds
mov ax,1017h
mov bx,0
mov cx,256
mov dx,cs
mov es,dx
mov dx,offset buffer
int 10h
mov dx,offset dta+30
mov ah,3ch
mov cx,0000
int1h
mov handle,ax
mov bx,handle
mov dx,offset buffer
mov cx,768
mov ah,40h
int1h

mov dx,0
mov cx,5
rewrite:
push cx

mov cx,65535
rr:
mov dl,cs:ddxx
call write
inc byte ptr cs:ddxx
pop cx
loop rewrite

jmp writeend
write proc near
mov ax,4f05h
mov bx,0
int 10h
mov dx,0
mov ax,0a000h
mov ds,ax
mov ah,40h
mov bx,cs:handle
int1h
ret
write endp

writeend:
mov ah,3eh
int1h
push cs
pop ds
mov bx,offset dta+35
mov al,[bx-1]
inc al
cmp al,58
jnz nn
mov cl,[bx-2]
inc cl
mov [bx-2],cl
mov al,'0'
nn:
mov [bx-1],al
quit :ret
savescr endp

init :
cli
push cs
pop ds
mov dx,offset dta
mov ah,1ah
int1h

mov dx,offset path
mov ah,4eh
mov cx,0
int1h

start:
cmp ax,0002
jz end
cmp ax,0003
je end
cmp ax,0018
je end

findnext:
mov dx,offset path
mov ah,4fh
int1h
jb end

jmp start

end:
mov si,offset dta+35
mov byte ptr [si],'$'
mov al,[si-1]
inc al
cmp al,58
jnz n
mov al,'0'
mov bl,[si-2]
inc bl
mov [si-2],bl
n:
mov [si-1],al

mov ah,9
mov dx,offset mess
int1h

mov dx,offset dta+30
int1h
mov si,offset dta+35
mov byte ptr [si],0

mov ax,3509h
int1h
mov di,offset int9
mov [di],bx
mov [di+2],es
push cs
pop ds
mov dx,offset new_int
mov ax,2509h
int1h
sti
mov dx,offset init
int7h
code ends
end begin