1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
| assume cs:codeseg, ds:dataseg, ss:stackseg
dataseg segment
mus_freq dw 262,262,262,196,330,330,330,262
dw 262,330,392,392,349,330,294
dw 294,330,349,349,330,294,330,262
dw 262,330,294,196,247,294,262,-1
mus_time dw 3 dup(12,12,25,25),12,12,50
dw 3 dup(12,12,25,25),12,12,50
dataseg ends
stackseg segment
db 100h dup (0)
stackseg ends
codeseg segment
start:
mov ax, stackseg
mov ss, ax
mov sp, 100h
mov ax, dataseg
mov ds, ax
lea si, mus_freq
lea di, mus_time
play:
mov dx, [si]
cmp dx, -1
je end_play
call sound
add si, 2
add di, 2
jmp play
end_play:
mov ax, 4c00h
int 21h
sound:
push ax
push dx
push cx
mov al,0b6h
; 8253芯片设置
out 43h,al
mov dx,12h
mov ax,34dch
div word ptr [si]
out 42h, al
mov al, ah
out 42h, a
;设置8255芯片, 控制扬声器的开/关
in al,61h
mov ah,al
or al,3
;延时
mov dx, [di]
wait1:
mov cx, 28000
delay:
nop
loop delay
dec dx
jnz wait
;恢复扬声器端口原值
mov al, ah
out 61h, al
pop cx
pop dx
pop ax
ret
codeseg ends
end start
|
