在 MASM 8086 程序集的屏幕上显示计时器

Display Timer on Screen in Assembly MASM 8086

我必须在屏幕上显示流逝的时间,我一直在网上寻找并找到如何设置时间延迟但我不知道如何在屏幕上显示它 这是我现在得到的(我什至不知道这是不是这样做的方法)

 delay proc 

    mov ah, 00
    int 1Ah
    mov bx, dx
 jmp_delay:
    int 1Ah
    sub dx, bx
    cmp dl, delaytime                                                      
    jl jmp_delay    
    ret
 delay endp 

可以使用几种方法:

  • 使用 DOS int 21h 显示文本(也许是函数 9?)。

  • 使用BIOS int 10h显示字符

  • 或者最后在B800:0000

  • 处直接写入屏幕

我个人会使用 BIOS 方法。

时间是一个数字,您需要将其转换为字符串才能显示。有很多程序可以做到这一点,接下来我 post 一个(程序 "dollars" 是次要的但必要的):

;------------------------------------------
;CONVERT A NUMBER IN STRING.
;ALGORITHM : EXTRACT DIGITS ONE BY ONE, STORE
;THEM IN STACK, THEN EXTRACT THEM IN REVERSE
;ORDER TO CONSTRUCT STRING (STR).
;PARAMETERS : AX = NUMBER TO CONVERT.
;             SI = POINTING WHERE TO STORE STRING.

proc number2string  
;FILL BUF WITH DOLLARS.
  push si
  call dollars
  pop  si

  mov  bx, 10 ;DIGITS ARE EXTRACTED DIVIDING BY 10.
  mov  cx, 0 ;COUNTER FOR EXTRACTED DIGITS.
cycle1:       
  mov  dx, 0 ;NECESSARY TO DIVIDE BY BX.
  div  bx ;DX:AX / 10 = AX:QUOTIENT DX:REMAINDER.
  push dx ;PRESERVE DIGIT EXTRACTED FOR LATER.
  inc  cx ;INCREASE COUNTER FOR EVERY DIGIT EXTRACTED.
  cmp  ax, 0  ;IF NUMBER IS
  jne  cycle1 ;NOT ZERO, LOOP. 
;NOW RETRIEVE PUSHED DIGITS.
cycle2:  
  pop  dx        
  add  dl, 48 ;CONVERT DIGIT TO CHARACTER.
  mov  [ si ], dl
  inc  si
  loop cycle2  

  ret
endp

;------------------------------------------
;FILLS VARIABLE WITH '$'.
;USED BEFORE CONVERT NUMBERS TO STRING, BECAUSE
;THE STRING WILL BE DISPLAYED.
;PARAMETER : SI = POINTING TO STRING TO FILL.

proc dollars                 
  mov  cx, 6
six_dollars:      
  mov  bl, '$'
  mov  [ si ], bl
  inc  si
  loop six_dollars

  ret
endp  

前面的程序可以显示时间,下一个例子显示如何使用它们,它也只显示秒(我相信你会自己显示分钟和小时),注意有两个重要的您必须在数据段中创建的变量:

seconds db ?         ;◄■■ IMPORTANT VARIABLES IN DATA SEGMENT.
buf     db 6 dup (?)


display_time:          
;▼ GET SYSTEM TIME.
  mov  ah, 2ch
  int  21h       ;◄■■ SECONDS RETURN IN DH. 
;▼ TIMER (1 SECOND).  
  cmp  dh, seconds
  je   display_time  ;◄■■ REPEAT UNTIL 1 SECOND PASSED.
  mov  seconds, dh
;▼ CONVERT SECONDS TO STRING.  
  xor  ax, ax  ;◄■■ NUMBER TO CONVERT TO STRING.
  mov  al, dh  ;◄■■ SECONDS IN AX.
  lea  si, buf  ;◄■■ VARIABLE WHERE STRING WILL BE STORED.
  call number2string  ;◄■■ CALL PROCEDURE THAT CONVERTS NUMBER TO STRING.
;▼ MOVE CURSOR TO 0,0.
  mov  dl, 0  ;◄■■ X.
  mov  dh, 0  ;◄■■ Y.
  mov  ah, 2
  mov  bh, 0
  int  10h  
;▼ DISPLAY STRING.
  mov  ah, 9
  lea  dx, buf
  int  21h
  jmp  display_time