music.asm

硬件端口发声程序

data segment
assume ds:data
freq dw 0,4552,4029,3617,3415
     dw 3042,2710,2415,2279
note db 3,2,1,2,3,3,3,2,2,2
     db 3,5,5,3,2,1,2,3,3,3
     db 3,2,2,3,2,1,-1
dl_time db 4,4,4,4,4,4,8,4,4,8
        db 4,4,8,4,4,4,4,4,4,4
        db 4,4,4,4,4,8
data ends

code segment
assume cs:code
main proc far
	mov ax,data
	mov ds,ax
	
	mov al,10110110b
	out 43h,al
	mov bx,0
	
play:
	mov al,note[bx]
	mov ah,dl_time[bx]
	inc bx
	push bx
	push ax
	cbw
	shl ax,1
	mov bx,ax
	mov ax,freq[bx]

	out 42h,al
	mov al,ah
	out 42h,al
	
	in al,61h
	or al,3
	out 61h,al

	mov ah,0
	int 1ah
	pop ax
	mov al,ah
	cbw
	add ax,dx
	mov bx,ax	
delay:
	mov ah,0
	int 1ah
	cmp bx,dx
	jnz delay

	in al,61h
	and al,0fch
	out 61h,al
	
	pop bx
	cmp  note[bx],-1

	jnz play


	mov ah,4ch
	int 21h
main endp
code ends
	end main