汇编语言改变字符的颜色

Question

这是一个基本的 DOSBox 程序，执行时会从左向右翻转屏幕。该程序运行良好。我遇到的唯一问题是我应该让所有非字母字符都是白底红字。更改非字母字符的颜色没有任何问题，但我不知道二进制红色与白色的组合。我以为是 11111100b 但这会使灰色变成红色，并且字符会闪烁。可能是非常简单的事情，但我无法弄清楚。有什么建议吗？

MyCode SEGMENT
        ASSUME CS:MyCode, DS:MyData   

MainProg  PROC                

    MOV     AX, MyData             
    MOV     DS, AX                 
    MOV     AX, 0B800h         
    MOV     ES, AX

    MOV BX, (25 * 160)                  ;BX contains value that equals row 25, column 0


    loop25: 

      SUB BX, 160                       ;Selects next row
      CALL flipRow                      ;Flips that row

      CMP BX, 0                         ;Have all rows been flipped?
    JNE loop25                          ;if not, repeat

    MOV     AH, 4Ch                
    INT     21h                   

MainProg ENDP  

flipRow  PROC                           ;PROC will flip each rown on verticle axis

    MOV DI, BX                          ;Puts row, column 0 in DI
    ADD DI, 158                         ;Adds 158 to DI to select right most character
    MOV SI, BX                          ;Puts row, column 0 in SI

 loopRow:                               ;loop until row is finished flipping

    MOV AX, ES: [DI]                    ;AX points to right most character
    MOV CX, ES: [SI]                    ;CX points to left most character
    MOV ES: [DI], CX                    ;Put left most character into right most place
  ;-------------------------------------------------------------------------
  CMP CL, 65                                 
  JL thenPart
  CMP CL, 91
  JL next
  CMP CL, 97
  JL thenPart                            ;Is the character Alphebetic? If not, color red on white
  CMP CL, 123                  
  JL next
  CMP CL, 122
  JG next
  thenPart:                                   
    MOV ES: [DI + 1], BYTE PTR 00FCh
  next:
  ;-------------------------------------------------------------------------
    MOV ES: [SI], AX                     ;Put right most character in left most place
  ;-------------------------------------------------------------------------
  CMP AL, 66                                
  JL then2
  CMP AL, 91
  JL next2
  CMP AL, 97
  JL then2                               ;Is the character Alphabetic? If not, color red on white
  CMP AL, 123
  JL next2
  CMP AL, 122
  JG next2
  then2:                                   
    MOV ES: [SI + 1], BYTE PTR 01111100b
  next2:
  ;-------------------------------------------------------------------------
    DEC DI
    DEC DI                               ;Move in left
    INC SI
    INC SI                               ;Move in right

  CMP SI, DI                             ;Is the row completely flipped? 
  JL loopRow                             ;If not, repeat
    RET
flipRow ENDP                 

MyCode ENDS

Answer 1

设计此颜色系统的 CGA/EGA/VGA 屏幕适配器有两种不同的文本颜色模式。

在其默认模式下，前景颜色有一个 'bright' 位——第 3 位，其中 2-1-0 用于 RGB——但 'background' 中的相同位部分是 'blink'。所以实际上你不能有 'bright' 背景。

可以使用低级别视频中断更改默认设置：

   AX = 1003h (operation code)
   BL = 00h (enable bold background)
or BL = 01h (enable blinking)
   INT 10h (execute operation)

（古老的记忆点动了 http://webpages.charter.net/danrollins/techhelp/0140.HTM 的 ctsy。）

汇编语言改变字符的颜色

Assembly Language Changing Color Of Characters

x86

assembly

vga

dosbox