跳转后计数器不起作用 - 汇编语言

Question

由于

某种原因，当我切换到鼠标输入切换回程序的键盘输入时，增加和减少计数器不起作用。它在我们输入字符的第一个循环中完美运行。这是程序，有什么建议吗？查看鼠标时间跳转后的速度跳转以供参考。CX计数器未更新或类似内容。（我不知道计数器是否没有更新，或者从鼠标时间切换到键时间后比较 CX 时出现问题。

    CLEAR   MACRO
    MOV AX,0600H
    MOV BH,07
    MOV CX,0000
    MOV DX,184FH
    INT 10H
  ENDM  
CURSOR  MACRO Col, Row
    MOV AH,02
    MOV BH,00
    MOV DL,Col
    MOV DH,Row
    INT 10H
  ENDM
DISP   MACRO MES
    MOV AH,09
    MOV DX,OFFSET MES
    INT 21H
ENDM
CLEARLINE MACRO ROW
    CURSOR 00,ROW
    DISP SPACES
    ENDM
ALWAYSONSCREENINFO MACRO
        CURSOR 16,00
        DISP TITLE1
        CURSOR 50,00
        DISP NAMES1 
        CURSOR 54,01
        DISP NAMES2
        CURSOR 33,7
        DISP MENU
        CURSOR 24,9
        DISP OPTION1
        CURSOR 24,10
        DISP OPTION2
        CURSOR 22,11
        DISP DASHES
        CURSOR 18,12
        DISP MOUSEMENU
        CURSOR 14,13
        DISP OPTION3
        CURSOR 8,14
        DISP OPTION4
        CURSOR 13,15
        DISP CHARMENU
        CURSOR 21,16
        DISP KILL
ENDM
.MODEL SMALL ; RUN THE PROGRAM IN DIMENSIONS 79x24 
.STACK 64H
.DATA
TITLE1          DB      'MICROPROCESSOR - EENG410','$'
NAMES1          DB      'name1 & name2','$'
NAMES2          DB      'std1         std2','$'
MENU            DB      'MENU','$'
OPTION1         DB      '1. Press "U" to Speed up the motor','$'
OPTION2         DB      '2. Press "D" to Slow Down the motor','$'
OPTION3         DB      '1. Right click the mouse to turn motor direction to clockwise','$'
OPTION4         DB      '2. Left click the mouse to turn the motor direction to anti-clockwise','$'
DASHES          DB      '----------------------------------------','$'
MOUSEMENU       DB      '(Press M to switch to the mouse options)','$'
CHARMENU        DB      '(Press the scroll button to switch back to fist 2 options)','$' 
SPEEDUP         DB      'DC motor is speeding up ','$'
SLOWDOWN        DB      'DC motor is slowing down','$'
RIGHT           DB      'DC motor will now rotate clockwise','$'
LEFT            DB      'DC motor will now rotate anti-clockwise','$'
KILL            DB      '-----To exit the program, press "E"-----','$'
PROGRAMEND1     DB      'Thank you for using our program','$'
PROGRAMEND2     DB      'The program has been terminated','$'
SPACES          DB      '                                                                                    ','$'
TRY             DB      'Please try again','$'
SPEEDNOW        DB      'Speed:','$'
DIRECTION       DB      'Motor Direction:','$'
CLOCK           DB      'Right','$'
COUNTER         DB      'Left  ','$'
N1              DB      '1','$'  
N2              DB      '2','$'
N3              DB      '3','$'
N4              DB      '4','$'
N5              DB      '5','$'
N6              DB      '6','$'
N7              DB      '7','$'
MAXSPEED        DB      'Max speed is 7','$'
MINSPEED        DB      'Min speed is 1','$'  
.CODE
MAIN:   MOV AX,@DATA
        MOV DS, AX
        CLEAR
        ALWAYSONSCREENINFO
        MOV CX,1
        CURSOR 28,21
        DISP SPEEDNOW
        CURSOR 35,21
        DISP N1
        CURSOR 22,22
        DISP DIRECTION
        CURSOR 39,22
        DISP CLOCK
        MOV CX,1
L0:     MOV AH,00   ;LOOP START
        INT 16H
        CMP AL,' '
        JE SPACED
        CMP AL,'U'
        JE FASTER
        CMP AL,'u'
        JE FASTER
        CMP AL,'D'
        JE SLOWER
        CMP AL,'d'
        JE SLOWER
        CMP AL,'M'
        JE MOUSETIME
        CMP AL,'m'
        JE MOUSETIME
        CMP AL,'E'
        JE EXIT
        CMP AL,'e'
        JE EXIT
        JNE TRYAGAINKEY
A1:     MOV AX,03
        INT 33H
        CMP BX,0
        JE A1
        CMP BX,1    ;MOUSE LEFT
        JE MRIGHT
        CMP BX,2    ;MOUSE RIGHT
        JE MLEFT
        CMP BX,3
        JE KEYTIME
SPACED: CLEARLINE 19
        JMP L0
FASTER: CLEARLINE 19
        CURSOR 27,19
        DISP SPEEDUP
        JMP INCREASE
SLOWER: CLEARLINE 19
        CURSOR 27,19
        DISP SLOWDOWN
        JMP DECREASE
MOUSETIME:  JMP A1
KEYTIME:    JMP L0
MRIGHT: CLEARLINE 19
        CURSOR 18,19
        DISP RIGHT
        JMP TRIGHT
MLEFT:  CLEARLINE 19
        CURSOR 18,19
        DISP LEFT
        JMP TLEFT
TRYAGAINKEY:    CLEARLINE 19
                CURSOR 28,19
                DISP TRY
                JMP L0 
INCREASE: CMP CX,7
          JE CANNOTINCREASESPEED
          INC CX
          JMP WHATSPEED
DECREASE: CMP CX,1
          JE CANNOTDECREASESPEED
          DEC CX
          JMP WHATSPEED
TRIGHT: CURSOR 39,22
        DISP CLOCK
        JMP A1
TLEFT:  CURSOR 39,22
        DISP COUNTER
        JMP A1
CANNOTINCREASESPEED:    CLEARLINE 19
                        CURSOR 27,19
                        DISP MAXSPEED
                        JMP L0
CANNOTDECREASESPEED:    CLEARLINE 19
                        CURSOR 27,19
                        DISP MINSPEED
                        JMP L0
WHATSPEED:  CMP CX,1
            JE N11
            CMP CX,2
            JE N22
            CMP CX,3
            JE N33
            CMP CX,4
            JE N44
            CMP CX,5
            JE N55
            CMP CX,6
            JE N66
            CMP CX,7
            JE N77
N11:    CURSOR 35,21
        DISP N1
        JMP L0
N22:    CURSOR 35,21
        DISP N2
        JMP L0
N33:    CURSOR 35,21
        DISP N3
        JMP L0
N44:    CURSOR 35,21
        DISP N4
        JMP L0
N55:    CURSOR 35,21
        DISP N5
        JMP L0
N66:    CURSOR 35,21
        DISP N6
        JMP L0
N77:    CURSOR 35,21
        DISP N7
        JMP L0
EXIT:   CLEAR
        CURSOR 21,12
        DISP PROGRAMEND1
        CURSOR 21,13
        DISP PROGRAMEND2
        MOV AH, 4CH
        INT 21H
    END MAIN

Answer 1

该

错误是由于鼠标中断33h函数AX=0003h返回鼠标位置CX和DX。

这将覆盖寄存器CX中的"计数器"。

在整个程序中将值保留在寄存器中始终是一个危险的游戏。最好有一个内存变量位置。

您也可以在执行鼠标功能之前尝试PUSH CX，然后在执行鼠标功能之后尝试POP CX，但您的程序结构和流程可能不利于这样做（我没有完全遵循它）。

此外，您的程序无法从（在您的上下文中）CX的荒谬值中恢复的原因是因为您使用的测试指令。例如这里

INCREASE: CMP CX,7
          JE CANNOTINCREASESPEED

您必须始终保持谨慎并捕获任何超出范围的值（即使您认为不会）

          JGE CANNOTINCREASESPEED

还与

CANNOTINCREASESPEED: MOV CX,7    ;clamp the value
...