模拟电子琴设计

              MOVAX,[BX]                   CALLT8253                   MOVCX,20h CON1:         PUSHCX                   CALLDISP                   POPCX                   LOOPCON1                   MOVDX,IOBPT                   MOVAL,00                  OUTDX,AL                   JMPREDIKEYT8253:        PUSHAX                   MOVAL,76h;计数器1,16位二进制,方式3。        MOVDX,CONTROL                   OUTDX,AL                   POPAX                   MOVDX,COUNT1                   OUTDX,AL                    MOVAL,AH                    OUTDX,AL                    RET;-------------------------DISPKEY:    CALLDISP                   CALLKEY                   MOVAH,AL;NEWKEY                   MOVBL,LTIME;LTIME                   MOVBH,lKEY;lKEY                   MOVAL,01h                   MOVDX,0FF21H