code	SEGMENT para public 'code'
	assume cs:code,ds:code
	locals
	.286

ORG	100h

.286
MAIN	PROC NEAR
 mov	ax,13h
 int	10h

 mov    bp,6000h	;6000h+7000h water segz,bp
			;6000h xor 1000h = 7000h

 mov	al,-1
 mov	es,bp
 mov	cx,-1
 xor	di,di
 rep	stosb

 xor	bp,1000h		;switch
 mov	es,bp
 dec	cx
 xor	di,di
 rep	stosb

;comment /*
 mov	dx,03c8h
 xor	ax,ax
 out	dx,al
 inc	dx
@asdf:
 mov	al,bl
 shr	al,3
 out	dx,al
; xor	al,al
 out	dx,al
 mov	al,bl
 shr	al,2
 out	dx,al
 inc	bx
 jnz	@asdf
;/*

; xor ax,ax
; int 33h

keypressed:
 xor bp,1000h			;switch

 mov es,bp

 mov ax,3
 int 33h
 shr cx,1

;^^^^^^^^^
;random rain drops, first one is from mouse

 mov bx,2
@rainy:
   mov ax,320
   mul dx
   add ax,cx
   cmp ah,0fah
;  cmp ax,320*200
   jb @@noclip
;     mov ax,64000
     mov ah,0fah
  @@noclip:
   mov di,ax
   mov ax,-1
   mov es:[di],ax
   mov es:[di+320],ax

   call @rand
   mov dx,ax
   call @rand
   mov cx,ax
 dec bx
 jnz @rainy

@noset:
 call	@advance_water
 call	@show_water

 in al,60h
 dec al
 jnz keypressed

 mov ax,03h
 int 10h
 ret
MAIN	ENDP

@rand:
 in ax,40h
 xor ax,randseed
 mov randseed,ax
ret

@advance_water:
 push   ds

 mov	ax,bp
 mov	bx,bp
 xor	bx,1000h
 mov	ds,ax
 mov	es,bx

 xor	di,di
 xor	dx,dx
@@adv_loop:
    xor cx,cx
    xor ax,ax
    mov dl,es:[di]
    mov cl,[di-321]
    mov al,[di-320]
    add ax,cx
    mov cl,[di-319]	
    add ax,cx
    mov cl,[di-1]	
    add ax,cx
    mov cl,[di+1]	
    add ax,cx
    mov cl,[di+319]	
    add ax,cx
    mov cl,[di+320]
    add ax,cx
    mov cl,[di+321]
    add ax,cx
    sar ax,2

    sub ax,dx
    mov cx,ax
    sar cx,9
    xor ax,cx

    mov es:[di],al
  dec	di
  jnz	@@adv_loop
  pop	ds
ret

@show_water:
 push   ds

;comment /*
 mov dx,03dah
 in al,dx
 test al,8
 jz $-3
 in al,dx
 test al,8
 jnz $-3
;/*

 mov	ds,bp
 push	0a000h
 pop	es
 mov    cx,64000/2
 xor    di,di
 xor    si,si
 rep    movsw

@@done:
 pop ds
ret

randseed dw ?

code	ends
	end main