任务编写一个简易电子音乐播放程序。基本要求将存储于内存中的音乐数据播出（格式自定义）。能够播出21个音阶（低音1~7、中音1~7、高音1~7）。扩展要求可以播出长短音（分长音、中音、短音）。可从文件中读音乐数据（格式自定义）。源码DATASEGMENTD1DB'*****************************************',0dh,0ah,'$'D2DB'*Thisisasimpleelectronic-piano*',0DH,0AH,'$'D3DB'*DesignedbyZZY,Studentid:20105495*',0DH,0AH,'$'D4DB'*Pleasefollowtheinstructions!*',0DH,0AH,'$'D5DB0dh,0ah,'1.EnterQtochoseedit(1-7)',0DH,0AH,'$'D6DB'2.EnterWtochoseplay',0DH,0AH,'$'D7DB'2-1.Enterzxctochoselowmidhigh',0DH,0AH,'$'D8DB'2-2.Entervbntochoseduanyinzhongyinchangyin',0DH,0AH,'$'D9DB'2-3.Press1-7toplay',0DH,0AH,'$'D10DB'3.Pressqtobackset',0dh,0ah,'$'D11DB'4.PressESCtoquit',0dh,0ah,0dh,0ah,'$'STR1DB100DB?DB100DUP(?)STR2DW100DUP(?)DATAENDSCODESEGMENTASSUMECS:CODE,DS:DATASTART:MOVAX,DATAMOVDS,AXLEADX,D1MOVAH,09HINT21HLEADX,D2MOVAH,09HINT21HLEADX,D3MOVAH,09HINT21HLEADX,D4MOVAH,09HINT21HLEADX,D1MOVAH,09HINT21HLEADX,D5MOVAH,09HINT21HLEADX,D6MOVAH,09HINT21HLEADX,D7MOVAH,09HINT21HLEADX,D8MOVAH,09HINT21HLEADX,D9MOVAH,09HINT21HLEADX,D10MOVAH,09HINT21HLEADX,D11MOVAH,09HINT21HQ1:MOVAH,0BH;检查键盘状态INT21H;DOS调用CMPAL,00H;有键按下？JZQ1;无键按下,转Q1MOVAH,01H;键盘输入并回显INT21HCMPAL,1BH;有键是ESC？JZQ2;是,退出CMPAL,'Q';是Q？JZQ3;编辑播放CMPAL,'W';是W？JZQ4;弹奏歌JMPQ1Q2:MOVAH,4CH;带返回码结束(是ESC结束)INT21HQ3:MOVDX,OFFSETSTR1MOVAH,0AHINT21HMOVDL,0AHMOVAH,02HINT21HMOVDL,0DHINT21HMOVSI,OFFSETSTR1+2MOVDI,OFFSETSTR2MOVCL,STR1+1MOVCH,0AGAIN:MOVAL,BYTEPTR[SI]CMPAL,'1'JZX1CMPAL,'2'JZX2CMPAL,'3'JZX3CMPAL,'4'JZX4CMPAL,'5'JZX5CMPAL,'6'JZX6CMPAL,'7'JZX7X1:MOVWORDPTR[DI],248JMPXX2:MOVWORDPTR[DI],278JMPXX3:MOVWORDPTR[DI],312JMPXX4:MOVWORDPTR[DI],330JMPXX5:MOVWORDPTR[DI],371JMPXX6:MOVWORDPTR[DI],416JMPXX7