基于汇编语言的电子琴设计（5）

LOAD_AUDIO PROC NEAR
；C/D调及对应的低、中、高频率分别载入
；OUT:BX
；IN:TUNE,AUDIO
TUNE_D: ；D大调判断
CMP TUNE,'D'
JNZ TUNE_CL ；不是判断是否是C调
TUNE_DL:
CMP AUDIO,1 ；低频判断
JNE TUNE_CM
LEA BX,LOWDD
JMP AUDIO_END
TUNE_DM:
CMP AUDIO,2 ；中频判断
JNE TUNE_CH
LEA BX,MIDD
JMP AUDIO_END
TUNE_DH:
LEA BX,HGHD ；高频判断
JMP AUDIO_END

TUNE_CL: ；C调处理
CMP AUDIO,1
JNE TUNE_CM
LEA BX,LOWD
JMP AUDIO_END
TUNE_CM:
CMP AUDIO,2
JNE TUNE_CH
LEA BX,MID
JMP AUDIO_END
TUNE_CH:
LEA BX,HGH

AUDIO_END:
RET
LOAD_AUDIO ENDP

SCAN_TUNE PROC NEAR
；C/D调判断及其状态在屏幕上的显示
；IN:DL 键盘扫描码
；OUT:TUNE
CMP DL,2EH ；判断是C否
JNZ NEXT_D ；不是则判断是D否
MOV TUNE,'C'
DRAW 55,38,60,41,0EH ；关D灯
DRAW 65,38,70,41,0AH ；开C灯
JMP TUNE_END ；结束
NEXT_D:
CMP DL,20H ；判断D否
JNZ TUNE_END
MOV TUNE,'D'
DRAW 55,38,60,41,0AH ；开D灯
DRAW 65,38,70,41,0EH ；关C灯
TUNE_END:
RET
SCAN_TUNE ENDP

SHOW_TEXT PROC NEAR
；在屏幕上显示字符
LEA DI,TEXT ；载入字符串首地址
MOV DH,[DI] ；赋行值
INC DI ；取得列
MOV DL,[DI] ；赋列值
MOV START_COL,DL ；保存开始列
MOV AH,2 ；设置光标位置
MOV BH,0 ；0页
INT 10H
INC DI ；取得颜色值
MOV BL,[DI] ；赋颜色值
CHAR_WRITE:
INC DI ；取得要显示的字符
MOV AL,[DI]
CMP AL,0FFH ；行结束否
JE BUMP_ROW ；下一行
CMP AL,0 ；结束否
JZ END_TEXT
CALL SHOW_CHAR ；显示字符
JMP CHAR_WRITE ；下一个字符
END_TEXT:
RET
BUMP_ROW:
INC DH ；下一行
MOV DL,START_COL ；赋开始列值
MOV AH,2 ；设光标位置
MOV BH,0
INT 10H
JMP CHAR_WRITE
SHOW_TEXT ENDP

SHOW_CHAR PROC NEAR
；显示字符
MOV AH,9 ；显示字符
MOV BH,0 ；0页
MOV CX,1
INT 10H
INC DL
MOV AH,2 ；设置光标位置
MOV BH,0 ；0页
INT 10H
RET
SHOW_CHAR ENDP

INIT PROC NEAR
；初始化屏幕：画琴键
MOV AX,DATA
MOV DS,AX

MOV AH,0 ；设置屏幕
MOV AL,0DH
INT 10H
MOV AH,0BH
MOV BH,0
MOV BL,00H ；背景色
INT 10H

CALL SHOW_TEXT ；显示字符串
DRAW 45,30,285,94,05H
DRAWSQRE 45,30,285,94,0DH
DRAWSQRE 49,48,280,49,00H

DRAW 55,38,60,41,0EH ；C调灯
DRAW 65,38,70,41,0AH ；D调灯
CALL SONG_LIGHT_OFF ；自动播放歌指示灯关

LEA SI,ST_LX ；画21个白色键
LEA DI,ED_LX
MOV CX,21
INIT_DRAW:
DRAW [SI],ST_Y,[DI],ED_Y,0FH
DRAW [SI],90,[DI],93,07H ；阴影
ADD SI,2
ADD DI,2
LOOP INIT_DRAW

LEA SI,BT_X ；画15个黑色键
LEA DI,BD_X
MOV CX,15
INIT_BLOCK:
DRAW [SI],BT_Y,[DI],BD_Y,00H
ADD SI,2
ADD DI,2
LOOP INIT_BLOCK

RET
INIT ENDP
SONG_LIGHT_OFF PROC NEAR
；关闭灯1~5
DRAW 271,42,275,46,09H
DRAW 265,42,269,46,09H
DRAW 259,42,263,46,09H
DRAW 253,42,257,46,09H
DRAW 247,42,251,46,09H

RET
SONG_LIGHT_OFF ENDP

FREQ_CHANGE PROC NEAR
;IN:DL 扫描码
CMP DELAY_TIME,600
JB CHANGE_ADD
CMP DELAY_TIME,60000
JA CHANGE_SUB
CMP DL,0CH ;-
JNZ FREQ_SUB
ADD DELAY_TIME,500
DRAW 271,38,274,41,0EH
JMP CHANGE_END
CHANGE_ADD:
ADD DELAY_TIME,500
JMP CHANGE_END
CHANGE_SUB:
SUB DELAY_TIME,500
JMP CHANGE_END
FREQ_SUB:
CMP DL,0DH ;+
DRAW 271,38,274,41,0AH
JNZ CHANGE_END
SUB DELAY_TIME,500
CHANGE_END:
RET
FREQ_CHANGE ENDP

EXIT PROC NEAR
；程序结束
MOV AH,4CH
INT 21H
RET
EXIT ENDP
CODE ENDS
END START

七、参考资料
〈IBM-PC汇编语言程序设计〉----清华大学出版社

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