用汇编语言写 体育比赛计时器并在dosbox 运行，有记忆的功能，程序运行开始计时，屏幕显示00:00:00，有记忆的功能，程序运行开始计时，屏幕显示00:00:00

好的，以下是汇编语言实现的体育比赛计时器示例代码：

.model small
.stack 100h

.data
hours db 0
minutes db 0
seconds db 0
last_hours db 0
last_minutes db 0
last_seconds db 0
memory_hours db 0
memory_minutes db 0
memory_seconds db 0
running db 1

.code
main proc

    mov ax, @data
    mov ds, ax

    ; Set up the timer interrupt
    mov ax, 3512h
    mov dx, offset newtimer
    mov ds:[int08h+2], dx
    mov dx, cs
    mov ds:[int08h], dx

    ; Display initial message
    mov ah, 2
    mov dl, 'P'
    int 21h
    mov dl, 'r'
    int 21h
    mov dl, 'e'
    int 21h
    mov dl, 's'
    int 21h
    mov dl, 's'
    int 21h
    mov dl, ' '
    int 21h
    mov dl, 'a'
    int 21h
    mov dl, 'n'
    int 21h
    mov dl, 'y'
    int 21h
    mov dl, ' '
    int 21h
    mov dl, 'k'
    int 21h
    mov dl, 'e'
    int 21h
    mov dl, 'y'
    int 21h
    mov dl, ' '
    int 21h
    mov dl, 't'
    int 21h
    mov dl, 'o'
    int 21h
    mov dl, ' '
    int 21h
    mov dl, 's'
    int 21h
    mov dl, 't'
    int 21h
    mov dl, 'a'
    int 21h
    mov dl, 'r'
    int 21h
    mov dl, 't'
    int 21h
    mov dl, ' '
    int 21h
    mov dl, 't'
    int 21h
    mov dl, 'h'
    int 21h
    mov dl, 'e'
    int 21h
    mov dl, ' '
    int 21h
    mov dl, 't'
    int 21h
    mov dl, 'i'
    int 21h
    mov dl, 'm'
    int 21h
    mov dl, 'e'
    int 21h
    mov dl, 'r'
    int 21h

    ; Wait for the user to start the timer
    mov ah, 0
    int 16h

    ; Main loop
main_loop:
    ; Check for user input
    mov ah, 1
    int 16h
    jnz stop_timer

    ; Wait for a short while
    mov cx, 1000
    mov dx, 8000h
    mov ah, 86h
    int 15h

    ; Increment the timer
    inc seconds
    cmp seconds, 60
    jne update_display
    mov seconds, 0
    inc minutes
    cmp minutes, 60
    jne update_display
    mov minutes, 0
    inc hours

update_display:
    ; Update the display if the time has changed
    cmp last_seconds, seconds
    je main_loop
    mov ah, 2
    mov dl, hours
    add dl, 30h
    int 21h
    mov dl, ':'
    int 21h
    mov dl, minutes
    add dl, 30h
    int 21h
    mov dl, ':'
    int 21h
    mov dl, seconds
    add dl, 30h
    int 21h
    mov last_hours, hours
    mov last_minutes, minutes
    mov last_seconds, seconds
    jmp main_loop

stop_timer:
    ; Save the current time to memory
    mov memory_hours, hours
    mov memory_minutes, minutes
    mov memory_seconds, seconds

    ; Restore the old timer interrupt
    mov ax, 3512h
    mov dx, ds:[int08h+2]
    mov ds:[int08h+2], dx
    mov dx, ds:[int08h]
    mov ds:[int08h], dx

    ; Display the saved time
    mov ah, 2
    mov dl, 13
    int 21h
    mov dl, 10
    int 21h
    mov dl, memory_hours
    add dl, 30h
    int 21h
    mov dl, ':'
    int 21h
    mov dl, memory_minutes
    add dl, 30h
    int 21h
    mov dl, ':'
    int 21h
    mov dl, memory_seconds
    add dl, 30h
    int 21h

    ; Wait for user input
    mov ah, 0
    int 16h

    ; Exit the program
    mov ah, 4ch
    int 21h

newtimer proc
    push ax
    push bx
    push cx
    push dx

    ; Increment the timer
    inc seconds
    cmp seconds, 60
    jne done
    mov seconds, 0
    inc minutes
    cmp minutes, 60
    jne done
    mov minutes, 0
    inc hours

done:
    ; Call the old timer interrupt
    mov ax, int08h
    mov bx, word ptr [ax+2]
    mov cx, word ptr [ax]
    push ds
    push bx
    push cx
    mov ds, word ptr [ax+4]
    call dword ptr [bx]
    pop cx
    pop bx
    pop ds

    pop dx
    pop cx
    pop bx
    pop ax
    iret
newtimer endp

int08h proc
    push ax
    push bx
    push cx
    push dx

    call dword ptr ds:[int08h+2]

    pop dx
    pop cx
    pop bx
    pop ax
    iret
int08h endp

end main

这段代码与前面的 C++ 代码相似，使用了一个中断来实现计时器。在主循环中，程序检查用户是否按下任何键来停止计时器。每次中断时，程序将更新时间并检查是否需要更新屏幕上的显示。

当用户停止计时器时，程序将保存当前时间并显示在屏幕上。程序将恢复旧的计时器中断，并等待用户按下任何键后退出程序。

请注意，这只是一个简单的示例程序，您可能需要根据实际需要进行更改和优化。