;**********************************************************
   ORG 0000H
   LJMP START
   ORG 000BH             ;中斷入口

   INC 20H               ;中斷服務程序,中斷計數器加1
   MOV TH0,#0D8H
   MOV TL0,#0EFH         ;12M晶振，形成10毫秒中斷
   RETI

START:
   MOV SP,#50H
   MOV TH0,#0D8H
   MOV TL0,#0EFH
   MOV TMOD,#01H
   MOV IE,#82H
MUSIC0:
   NOP
   MOV DPTR,#DAT        ;表頭地址送DPTR
   MOV 20H,#00H         ;中斷計數器清0
   MOV B,#00H           ;表序號清0
MUSIC1:
   NOP
   CLR A
   MOVC A,@A+DPTR       ;查表取代碼
   JZ END0              ;是00H,則結束
   CJNE A,#0FFH,MUSIC5
   LJMP MUSIC3
MUSIC5:
   NOP
   MOV R6,A
   INC DPTR
   MOV A,B
   MOVC A,@A+DPTR       ;取節拍代碼送R7
   MOV R7,A
   SETB TR0             ;啟動計數
MUSIC2:
   NOP
   CPL P2.4
   MOV A,R6
   MOV R3,A
   CPL A
   MOV P1,A             ;顯示(修改者加入的顯示)
   CPL A
   LCALL DEL
   MOV A,R7
   CJNE A,20H,MUSIC2    ;中斷計數器(20H)=R7否?
                        ;不等,則繼續循環
   MOV 20H,#00H         ;等于,則取下一代碼
   INC DPTR
   LJMP MUSIC1
MUSIC3:
   NOP
   CLR TR0              ;休止100毫秒
   MOV R2,#0DH
MUSIC4:
   NOP
   MOV R3,#0FFH
   LCALL DEL
   DJNZ R2,MUSIC4
   INC DPTR
   LJMP MUSIC1
END0:
   NOP
   MOV R2,#64H          ;歌曲結束,延時1秒后繼續
MUSIC6:
   MOV R3,#00H
   LCALL DEL
   DJNZ R2,MUSIC6
   LJMP MUSIC0
DEL:
   NOP
DEL3:
   MOV R4,#05H
DEL4:
   NOP
   DJNZ R4,DEL4
   NOP
   DJNZ R3,DEL3
   RET

DAT:
DB 18H, 30H, 1CH, 10H
DB 20H, 40H, 1CH, 10H
DB 18H, 10H, 20H, 10H
DB 1CH, 10H, 18H, 40H
DB 1CH, 20H, 20H, 20H
DB 1CH, 20H, 18H, 20H
DB 20H, 80H, 0FFH,20H
DB 30H, 1CH, 10H, 18H
DB 20H, 15H, 20H, 1CH
DB 20H, 20H, 20H, 26H
DB 40H, 20H, 20H, 2BH
DB 20H, 26H, 20H, 20H
DB 20H, 30H, 80H, 0FFH
DB 20H, 20H, 1CH, 10H
DB 18H, 10H, 20H, 20H
DB 26H, 20H, 2BH, 20H
DB 30H, 20H, 2BH, 40H
DB 20H, 20H, 1CH, 10H
DB 18H, 10H, 20H, 20H
DB 26H, 20H, 2BH, 20H
DB 30H, 20H, 2BH, 40H
DB 20H, 30H, 1CH, 10H
DB 18H, 20H, 15H, 20H
DB 1CH, 20H, 20H, 20H
DB 26H, 40H, 20H, 20H
DB 2BH, 20H, 26H, 20H
DB 20H, 20H, 30H, 80H
DB 20H, 30H, 1CH, 10H
DB 20H, 10H, 1CH, 10H
DB 20H, 20H, 26H, 20H
DB 2BH, 20H, 30H, 20H
DB 2BH, 40H, 20H, 15H
DB 1FH, 05H, 20H, 10H
DB 1CH, 10H, 20H, 20H
DB 26H, 20H, 2BH, 20H
DB 30H, 20H, 2BH, 40H
DB 20H, 30H, 1CH, 10H
DB 18H, 20H, 15H, 20H
DB 1CH, 20H, 20H, 20H
DB 26H, 40H, 20H, 20H
DB 2BH, 20H, 26H, 20H
DB 20H, 20H, 30H, 30H
DB 20H, 30H, 1CH, 10H
DB 18H, 40H, 1CH, 20H
DB 20H, 20H, 26H, 40H
DB 13H, 60H, 18H, 20H
DB 15H, 40H, 13H, 40H
DB 18H, 80H, 00H
   end