cseg               segment
                   assume    cs:cseg
                   org       100h
first:             jmp       init

olint              label     WORD
old8               dd        ?

newint:
                   push      ax
                   push      bx
                   push      cx
                   push      dx
                   push      bp
                   push      si
                   push      di
                   push      ds
                   push      es
                   push      ss
                   mov       ah,1
                   xor       cx,cx
                   xor       dx,dx
                   int       1ah
                   pushf
                   call      old8
                   pop       ss
                   pop       es
                   pop       ds
                   pop       di
                   pop       si
                   pop       bp
                   pop       dx
                   pop       cx
                   pop       bx
                   pop       ax
                   iret
init:
                   mov       ax,3508h
                   int       21h
                   mov       olint,bx
                   mov       olint[2],es
                   mov       ax,2508h
                   lea       dx,newint
                   int       21h
                   mov       ax,ds:[2ch]
                   mov       es,ax
                   mov       ah,49h
                   int       21h
                   lea       dx,init
                   int       27h
cseg               ends
                   end       first