汇编器使用段寄存器

Question

最近，我正在编写程序集，并且我编写的程序在DOSBox下运行没有任何问题。现在，我需要使用DOS将同一程序移植到实际计算机中，但是会出现一些问题。

首先，在DOSBox下，我正在使用ML进行编译，但是在真正的PC上，一旦输入ML，它就会说：

该程序不能在DOS模式下运行。

因此，我一直在寻找一种解决方案，并发现MASM可以毫无问题地编译asm程序。不幸的是，我需要移植的程序在编译时报告严重错误（仅1种类型）。

错误A2061：段寄存器使用不当

出现这些问题的路线如下

...
CARLOC EQU $-2
...
MOV [WORD PTR DS:CARLOC],DX
...

以下代码也会出现相同的问题

...
MOV ES,CX
MOV AL, [BYTE PTR ES:0017H]
...

到目前为止，我已经尝试将BYTE PTR [ES:0017H] 产生相同错误的BYTE PTR更改为

并BYTE PTR ES:0017H 成功地在 其中编译了代码，该程序运行了但无法正常运行

注意：我不知道当前在哪种架构下工作。可能无法物理访问该计算机，但是如果我可以键入一些代码来查看屏幕上的信息，我将很高兴这样做。

代码在这里，如果我需要在这里粘贴它就太长了，然后确定，但是直到那时https://pastecode.xyz/view/5f332efc

PC说它运行MSDOS 6

Answer 1

（更新：Michael Petch说一些与 MASM或MASM兼容的汇编器允许在括号内使用大小和段覆盖。但是update2：并非全部，因此这实际上可能是问题所在。至少是标准样式，因此我建议始终这样做）

使用所需的常规MASM语法MOV [CARLOC], DX。 根据您声明的方式carloc，您可能仍然需要mov word ptr [CARLOC], dx，但是DS:已经是默认段。

如果您想对此进行明确说明，MOV word ptr ds:[CARLOC], dx但我建议在asm源代码中省略冗余DS前缀，因为某些汇编程序的机器代码中包括冗余DS前缀！DS：唯一不是唯一的时间是当与，ds:[bp]或ebp或一起使用时ds:[esp]，这暗示SS是默认段。

对于MASM，ds:还需要数字绝对地址作为前缀。否则，将其视为立即目的地（不考虑方括号），而该目的地当然不是目的地。使用这样的定义CARLOC equ $-2，您将需要ds:[CARLOC]。显然，MASM不会ds在机器代码中添加无用的前缀，因此您不必担心该汇编程序。

如果需要CS / DS / ES / FS / GS / SS前缀，则标准语法是将其放在方括号之外：

MOV AL, ES:[0017H]

AL目的地表示byte ptr操作数大小，该大小也超出了括号。例如，查看反汇编程序输出。

并BYTE PTR ES:0017H成功地将代码编译到其中，

是的，这是有效的语法：方括号在某些情况下是可选的（包括绝对地址或符号）。许多人建议始终在存储操作数周围使用括号（而不是OFFSET symbol立即数），以使读者更容易理解。

如果您要使用方括号，它们会在size ptr和seg:替代之后。

该程序已运行但无法正常运行

然后，您的代码中除了语法错误之外，还有其他错误。

或者，如果您尝试将其构建为Windows可执行文件：当然，将为DOS编写的代码（实模式，在整个计算机的控制下）并以32位或64位构建为代码是行不通的Windows可执行文件（保护模式或64位模式，在操作系统下为Ring 3）。系统调用ABI甚至API也完全不同：它们是不同的操作系统，而DOS API对Windows可执行文件不可用。

Michael还建议，USE32或其他指令可能会使MASM试图将您从自己身上救出来，并拒绝在应该与平面内存模型一起运行的代码中使用分段。但是，如果es:[17H]可行，那可能不是。

Answer 2

目前还不清楚我应该回答这个问题的哪一部分。

• 最初的错误与拼写错误有关。DS本来应该DX

• 您使用的 MASM 版本 5.10 不支持方括号内的段和大小覆盖[]。代码如下：

  MOV     [WORD PTR DS:CARLOC],DX
  

  需要写成：

  MOV     WORD PTR DS:[CARLOC],DX
  

• 您使用的 MASM 和 LINK 版本不会生成 COM 程序。您需要一个以前与 DOS 一起提供的名为 EXE2BIN 的程序，它可以将某些类型的 EXE 程序转换为 COM。你必须像这样运行 EXE2BIN：

  EXE2BIN progname.exe progname.com
  

• 据我所知，MASM 的版本不支持简化的段指令.MODEL、.CODE、.DATA、 ，.STACK因此需要删除它们。

您可以修改代码以作为 EXE 程序运行，而不是使用 EXE2BIN 从 EXE 转换为 COM 程序。删除行：

    .MODEL  TINY
    .CODE
    .ORG 100h

创建一个STACK类似于以下内容的段：

STACK SEGMENT STACK
    db 512 DUP(?)
STACK ENDS

EXE 程序需要在程序启动时尽早初始化DS（如果需要，还可以初始化ES ）。这与 COM 程序不同，其中CS=DS=ES=SS，并且不需要此类初始化。您可以添加这些行来初始化DS：

    MOV     AX, CODE                ; Initialize the Code Segment
    MOV     DS, AX

您将所有数据放入CODE段中，因此需要将DS初始化为与 相同CODE。

应作为 EXE 运行的程序的最终版本是：

        TITLE   FormulaONE TURBO (256 byte game)


STACK SEGMENT STACK
    db 512 DUP(?)
STACK ENDS

CODE    SEGMENT BYTE PUBLIC 'CODE'
        ASSUME  CS:CODE,DS:CODE

;--------------------------------------------------------------------------
;                       ACTUAL PROGRAM BEGINS HERE
;--------------------------------------------------------------------------
START:
        MOV     AX, CODE                ; Initialize the Code Segment
        MOV     DS, AX
        MOV     BP,AX                   ; Reset score to 0 (=MOV BP,0)
        MOV     AH,06H                  ; Clear Screen and home the cursor
        CALL    SCROLL
;--------------------------------------------------------------------------
;                             MAIN GAME LOOP
;--------------------------------------------------------------------------
GAME:
        MOV     DX,1629H                ; Load CAR loc (LINE 16H, COL 29H)
CARLOC  EQU     $-2                     ; Self modifying code (CAR loc)

        CALL    MOVEIT                  ; Move cursor to DH,DL (car loc)
;--------------------------------------------------------------------------
;  Erase the car at old screen location
;--------------------------------------------------------------------------
        MOV     AL,20H                  ; Print 5 spaces
        PUSH    AX
        OUT     61H,AL                  ;   Turn off speaker (AL=00100000b)
        MOV     BL,70H                                                ;^^
        MOV     CL,5
        INT     10H

        MOV     AX,0E0AH                ; Move cursor to next line
        INT     10H

        POP     AX                      ; Print 5 more spaces
        INT     10H
;--------------------------------------------------------------------------
;  Move to new car location based on shift key status
;--------------------------------------------------------------------------
        MOV     CL,40H                  ; Get shift key status
        MOV     ES,CX                   ;   (=MOV ES,0040H)
        MOV     AL,BYTE PTR ES:[0017H]

        TEST    AL,1                    ; Right SHIFT key pressed?
        JZ      TRYLFT                  ;    No...Try left shift
        INC     DX                      ;    Yes..move car right 1 space
TRYLFT: TEST    AL,2                    ; Left SHIFT key pressed?
        JZ      KEYEND                  ;    No...done checking keys
        DEC     DX                      ;    Yes..move car left 1 space
KEYEND: MOV     WORD PTR DS:[CARLOC],DX ; Save new car location in memory
                                        ; (That is the self-modifying part)
        PUSH    DX                      ; Save car location on stack also
;--------------------------------------------------------------------------
;  Scroll the track down one line
;--------------------------------------------------------------------------
        MOV     AX,0701H                ; Scroll screen down 1 line
        CALL    SCROLL                  ;   this also sets BH=0 and BL=2
                                        ;   and homes the cursor

        MOV     CL,40                   ; Print left side of track
LMARGN  EQU     $-1                     ;   (Pointer to Left Margin)
        INT     10H

        MOV     DX,CX                   ; Find right side of track position
        ADD     DX,26                   ;   (Starting track width = 26)
TRKWID  EQU     $-1                     ;   (Pointer to Track Width)
        MOV     CL,80
        SUB     CX,DX
        CALL    MOVEIT                  ; Move cursor to right side of track
        INT     10H                     ; Print grass on right side of track
;--------------------------------------------------------------------------
;  Print the score in the lower right corner of the screen
;--------------------------------------------------------------------------
        MOV     DX,184EH                ; Screen loc 77,25 bottom right
        CALL    MOVEIT                  ; Move cursor to score location
        MOV     AX,BP                   ; Move Score to AX
        MOV     CL,8                    ; Shift score right 8 bits
        SAR     AX,CL                   ; (This makes it hard to get to Z!)
        ADD     AX,0E00H+65             ; MOV AH,0Eh & Convert score to A-Z
        INT     10H                     ; Print the score on the screen
;--------------------------------------------------------------------------
;  Check for a collision
;--------------------------------------------------------------------------
        POP     DX                      ; Restore car location from stack
        CALL    MOVEIT                  ; Move cursor under left front tire
        JNZ     PCAR                    ; Hit something? Yes... Print our
                                        ;   red car and exit the game
        PUSH    DX                      ; Save left tire position to stack
        ADD     DL,4                    ; Move cursor under right front tire
        CALL    MOVEIT                  ; Check to see if we hit something
        POP     DX                      ;    Restore our car position
        JNZ     PCAR                    ; Hit something? Yes... Print our
                                        ;   red car and exit the game
        PUSH    DX                      ; Save car position to stack
;--------------------------------------------------------------------------
;  No collision, go ahead and print our car (red)
;--------------------------------------------------------------------------
        CALL    PCAR                    ; Print our red car (CX=8)
;--------------------------------------------------------------------------
;  Slow game down by waiting for 3 vertical retraces and play sound effects
;--------------------------------------------------------------------------
        MOV     CL,3                    ; CX is delay invertical retraces
DELAY:  MOV     DX,03DAH                ; Video screen port
HERE:   IN      AL,DX                   ; Get current video status
        TEST    AL,8                    ; Check vertical retrace bit
        JNE     HERE                    ; Wait for 1 full vertical retrace
HERE2:                                  ; Turn on and off speaker...
        ADD     AL,BYTE PTR DS:[005DH]  ;   (Check command line for Q)
        DEC     AX                      ;   (which is for Quiet mode.)
        OUT     61H,AL                  ; while waiting for screen refresh
        IN      AL,DX
        TEST    AL,8
        JE      HERE2
        LOOP    DELAY                   ; Go wait for another until CX=0
;--------------------------------------------------------------------------
;  Keep track of our current score
;--------------------------------------------------------------------------
        INC     BP                      ; Count lines printed so far (score)
;--------------------------------------------------------------------------
;  Adjust size and placement of track
;--------------------------------------------------------------------------
        POP     DX                      ; Restore our car position fm stack
        MOV     AX,BP                   ; TEST AL=2 bytes, TEST BP=4 bytes

        TEST    AL,255                  ; Make track smaller each 256 lines
        JNZ     NOCHG                   ;   Go around if not time for change
        DEC     BYTE PTR DS:[TRKWID]    ;   Change width (Self-mod code!)
NOCHG:

        TEST    AL,9                    ; Make track wavy every so often
        JNZ     ENEMY                   ;  Time to go straight
        TEST    AL,128                  ;  Left or right?
        JZ      LEFT
        ADD     BYTE PTR DS:[LMARGN],2  ; -Move right 2 spaces (Self-mod!)
;        INC     DX                      ;    Make sure that enemy car
;        INC     DX                      ;      stays ON the track. (TAI)
LEFT:   DEC     BYTE PTR DS:[LMARGN]    ; -Move left 1 space   (Self-mod!)
;        DEC     DX                      ;    Make sure that enemy car
                                        ;      stays ON the track. (TAI)
;--------------------------------------------------------------------------
;  Draw an opponent car every 15 screen lines
;--------------------------------------------------------------------------
ENEMY:                                  ; Our car position is in DX register
        MOV     DH,0                    ; Make it into enemy position using
                                        ; True Artificial Intellegence (tm)
                                        ; ^    ^          ^  TAI :-)
        TEST    AL,15                   ; Every 15 lines print enemy car
        MOV     AX,OFFSET GAME          ;    Prepare for RET below
        PUSH    AX                      ;    Use RET as a jump to GAME loop
        JNZ     GOBACK                  ; Not time yet to print enemy car
;--------------------------------------------------------------------------
;                PRINT CAR AT SCREEN LOCATION "DX"
;
; On entry:  DH points to line, DL to column, CX to car graphic offset
;                                             (8 for red, 0 for blue car)
; On exit:  The proper car will be drawn.  Also, if we used CALL PCAR to
;           get here we will be returned into the program at that point.
;           If we used JNZ PCAR to get here we will be returned to the
;           DOS prompt (the game will end).
;--------------------------------------------------------------------------
PCAR:
        PUSH    BP                      ; Save our current score counter
        MOV     BP,OFFSET CAR2          ; Point to the car graphic
        ADD     BP,CX                   ;   Add offset to proper car
        SUB     BYTE PTR [BP+4],24      ; Print stripe on hood of car
        MOV     AX,1302H                ; Print the car to the screen
        PUSH    AX                      ;    AX may change in INT 10h call
        MOV     CL,5                    ;    Graphic is 5 characters wide
        PUSH    DS                      ;    It is located in the data seg
        POP     ES                      ;      but INT 10h needs that in ES
        INT     10H                     ; Print the first line of the car
        ADD     BYTE PTR [BP+4],24      ; Print cockpit and rear stripe
        POP     AX                      ; (=MOV AX,1302H)
        INC     DH                      ; Point to next line of the screen
        INT     10H                     ; Print the second line of the car
        POP     BP                      ; Restore current score counter
GOBACK: RET
CAR2:  
        DB      0DCH,70H,0DEH,71H,0D2H,1FH,0DDH,71H     ; Blue car graphic
        DB      0DCH,70H                                ;   Common tire
        DB      0DEH,74H,0D2H,4EH,0DDH,74H,0DCH,70H     ; Red car graphic
;--------------------------------------------------------------------------
;                     SCROLL SCREEN DOWN "AL" LINES
;                      (or if AH=6, clear screen)
;
; On entry:  AH must be 7, AL must be number of lines to scroll (1)
; On exit:   BH will be 0, BL will be 2 and we will fall through to
;            MOVEIT to home the cursor.             ^^^^^^^^^^^^
;--------------------------------------------------------------------------
SCROLL:
        MOV     BH,70H                  ; Use Black on Gray (road color)
        XOR     CX,CX                   ;   From UL corner (=MOV CX,0)
        MOV     DX,184FH                ;   to LR corner
        INT     10H
        MOV     BX,02                   ; Set BH to 0 and BL to 2 for use
                                        ;   when we return.
        XOR     DX,DX                   ; Now, home the cursor  (=MOV DX,0)
;--------------------------------------------------------------------------
;                  MOVE CURSOR TO SCREEN LOCATION DH,DL
;               AND SEE IF THERE IS A SPACE (TRACK) THERE
;
; On entry:  DH is screen line, DL is screen column
; On exit:   Z flag will be set/reset if there is a space character
;            under the cursor and AH will be 9 and AL will be 0DBh
;--------------------------------------------------------------------------
MOVEIT:
        MOV     AH,2                    ; Move cursor to DH,DL
        INT     10H
        MOV     AH,8                    ; Get the character under cursor
        INT     10H
        CMP     AL,20H                  ; Is it a space? (set Z flag)
        MOV     AX,09DBH                ; Set AH to 9 and AL to 0DBh for
        RET                             ;  use just after we return (don't
                                        ;  worry, Z flag will still be set)
CODE    ENDS

        END     START

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Re: Stackoverflow question a2061
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Your paste - Paste your paste here
        TITLE   FormulaONE TURBO (256 byte game)
;==========================================================================
;      FormulaONE TURBO Copyright 1995, 1996, 1998 by David S. Issel
;                          all rights reserved.
;
;                      Written using Turbo Assembler
;
;                     To assemble use:  TASM F1-TURBO
;                         To link use:  TLINK /x/t F1-TURBO
;
; For Microsoft Macro Assembler 6.0 use:  ML /AT F1-TURBO.ASM
;
;
;               To run FormulaONE use:  F1-TURBO
;     To run FormulaONE without sound:  F1-TURBO Q
;
;  Use left and right shift keys to control your car                  __,        
;  at bottom of screen.  Try not to run into anything       _ _.--'-n_/          
;  for as long as you can.                                -(_)------(_)=         
;==========================================================================
        .MODEL  TINY
        .CODE
CODE    SEGMENT BYTE PUBLIC 'CODE'
        ASSUME  CS:CODE,DS:CODE
        ORG     0100H                   ; This will be a COM file
;--------------------------------------------------------------------------
;                       ACTUAL PROGRAM BEGINS HERE
;--------------------------------------------------------------------------
START:
        MOV     BP,AX                   ; Reset score to 0 (=MOV BP,0)
        MOV     AH,06H                  ; Clear Screen and home the cursor
        CALL    SCROLL
;--------------------------------------------------------------------------
;                             MAIN GAME LOOP
;--------------------------------------------------------------------------
GAME:
        MOV     DX,1629H                ; Load CAR loc (LINE 16H, COL 29H)
CARLOC  EQU     $-2                     ; Self modifying code (CAR loc)

        CALL    MOVEIT                  ; Move cursor to DH,DL (car loc)
;--------------------------------------------------------------------------
;  Erase the car at old screen location
;--------------------------------------------------------------------------
        MOV     AL,20H                  ; Print 5 spaces
        PUSH    AX
        OUT     61H,AL                  ;   Turn off speaker (AL=00100000b)
        MOV     BL,70H                                                ;^^
        MOV     CL,5
        INT     10H

        MOV     AX,0E0AH                ; Move cursor to next line
        INT     10H

        POP     AX                      ; Print 5 more spaces
        INT     10H
;--------------------------------------------------------------------------
;  Move to new car location based on shift key status
;--------------------------------------------------------------------------
        MOV     CL,40H                  ; Get shift key status
        MOV     ES,CX                   ;   (=MOV ES,0040H)
        MOV     AL,[BYTE PTR ES:0017H]

        TEST    AL,1                    ; Right SHIFT key pressed?
        JZ      TRYLFT                  ;    No...Try left shift
        INC     DX                      ;    Yes..move car right 1 space
TRYLFT: TEST    AL,2                    ; Left SHIFT key pressed?
        JZ      KEYEND                  ;    No...done checking keys
        DEC     DX                      ;    Yes..move car left 1 space
KEYEND: MOV     [WORD PTR DS:CARLOC],DX ; Save new car location in memory
                                        ; (That is the self-modifying part)
        PUSH    DX                      ; Save car location on stack also
;--------------------------------------------------------------------------
;  Scroll the track down one line
;--------------------------------------------------------------------------
        MOV     AX,0701H                ; Scroll screen down 1 line
        CALL    SCROLL                  ;   this also sets BH=0 and BL=2
                                        ;   and homes the cursor

        MOV     CL,40                   ; Print left side of track
LMARGN  EQU     $-1                     ;   (Pointer to Left Margin)
        INT     10H

        MOV     DX,CX                   ; Find right side of track position
        ADD     DX,26                   ;   (Starting track width = 26)
TRKWID  EQU     $-1                     ;   (Pointer to Track Width)
        MOV     CL,80
        SUB     CX,DX
        CALL    MOVEIT                  ; Move cursor to right side of track
        INT     10H                     ; Print grass on right side of track
;--------------------------------------------------------------------------
;  Print the score in the lower right corner of the screen
;--------------------------------------------------------------------------
        MOV     DX,184EH                ; Screen loc 77,25 bottom right
        CALL    MOVEIT                  ; Move cursor to score location
        MOV     AX,BP                   ; Move Score to AX
        MOV     CL,8                    ; Shift score right 8 bits
        SAR     AX,CL                   ; (This makes it hard to get to Z!)
        ADD     AX,0E00H+65             ; MOV AH,0Eh & Convert score to A-Z 
        INT     10H                     ; Print the score on the screen
;--------------------------------------------------------------------------
;  Check for a collision
;--------------------------------------------------------------------------
        POP     DX                      ; Restore car location from stack
        CALL    MOVEIT                  ; Move cursor under left front tire
        JNZ     PCAR                    ; Hit something? Yes... Print our
                                        ;   red car and exit the game
        PUSH    DX                      ; Save left tire position to stack
        ADD     DL,4                    ; Move cursor under right front tire
        CALL    MOVEIT                  ; Check to see if we hit something
        POP     DX                      ;    Restore