          ᥬ  IBM PC.  17.                            1


           17
          ------------------------------------------------------------
          
          ᪮  III: ७ 㭪樨 DOS
          
          :   ७묨 㭪ﬨ DOS, 稭 
          ᨨ 2.0  ࠡ⪨ ᪮ 䠩. 
          
          
          ------------------------------------------------------------
             㭪樨  ᨨ DOS  ࠡ⪨  䠩, 
             16,  ⢨⥫     ᫥ ᨩ
          DOS.      ७ 㭪権, 
             DOS 2.0  3.0   ন  ࠭ 
          .  ०,  祬  믮 ᪮  樨 
           , ᫥ 㡥  稨 室 ᨨ
          DOS.
               ७ 㭪権  ᢮   
           ᨨ DOS.    㪮⢠  DOS ४ ᯮ
             㭪樨,    ⢥  ⥬
          ⨯ UNIX.    樨  ᯮ짮 ப
           ଠ ASCIIZ    砫쭮  ⠭  ᪮, 
          㯠    䠩;    䠩  ᫥⥫쭮
          㯠  䠩; ᯥ樠  .  
          
             ASCIIZ
          ------------------------------------------------------------
               ᯮ짮    ७ 㭪権  ᪮
           権 室 ᮮ DOS  ப   ଠ
          ASCIIZ,  ᮤঠ饩 䨪 䠩    ᪮-
          ,   㯠   䠩 ( ࠬ 易⥫
          )    ப    ⭠ 㫥,
          ਬ:
                       PATHNM1    DB    'B:\TEST.ASM',0
                       PATHNM2    DB    'C:\UTILITY\NU.EXE',0
             
             ⭠  (  ﬠ )  ᯮ  
           ࠧ⥫. 㫥  (zero) 蠥 ப (
           ASCIIZ ଠ).   뢠, ᯮ  
          ⢥ ࠬ ASCIIZ ப,   ⮩ ப 㦠
            ॣ DX, ਬ,   LEA  DX,PATHNM1.
             
              
          ------------------------------------------------------------
             樨 ᮧ     䠩  ॡ  㧪 
          ॣ AX 塠⮢ ᫠,  ।⠢饣 ᮡ 䠩
           .    8 ,   ⠭  ன⢠
            㦤    樨        ᯮ짮
          ।⢥ 䠩 :  0  -  , 1 - 뢮, 2 -
          뢮 ᮮ饭  訡, 3 - 譥 ன⢮, 4 - ਭ
          .



          
          ᥬ  IBM PC.  17.                            2


              㯠    ᮧ    ⨨  䠩 
           ASCIIZ ப  㭪樨 DOS .  3C   3D. 
          譠  ⠭ 䫠  CF  0   頥 䠩
             ॣ AX.     室  ࠭ 
            DW  ᯮ짮      ᫥
          権  ᪮ 䠩.    ᯥ譮 樨 䫠
          CF ⠭  1,    ॣ AX 頥  訡-
          , 騩  樨 (.⠡.17.1).
             
               01   訡  㭪樨
               02     
               03    㯠  
               04    ᫨誮  䠩
               05    㯠 ( ⢥࣭)
               06   訡 䠩 
               07    ࠢ  ࠧ襭
               08   筮 
               09   訡   
               10   訡 㤮
               11   訡 ଠ
               12   訡  㯠
               13   訡 
               15   訡 ᪮
               16   ⪠ 㤠 
               17   㣮 ன⢮  ?
               18     䠩
             
            
          ------------------------------------------------------------
               ᫥ ࠧ    ॡ  ᮧ,
              ᪮  䠩    ७ ᨨ
          DOS.
              䠩: .3C
              ᮧ  䠩  ९뢠 ண 䠩
          ᯮ  㭪 .3C.   ⮬  ॣ  DX 
          ᮤঠ   ASCIIZ-ப,   ॣ CX  - 室
          ਡ.   ਡ  ᬮ७   15;  筮
           䠩 祭 ਡ - 0.
             ᬮਬ ਬ ᮧ 筮 䠩:
             
               MOV  AH,3CH         ;   ᮧ
               MOV  CX,00          ;    筮 䠩
               LEA  DX,PATHNM1     ; ASCIIZ ப
               INT  21H            ; 맮 DOS
               JC   error          ; 室  訡
               MOV  HANDLE1,AX     ; ࠭ 䠩   DW
             
              ࠢ쭮  ⨨    ᮧ  
               ਡ⮬,  頥 䫠 CF  ⠭
          䠩   ॣ  AX.       ᯮ짮
             ᫥ 権.  ᫨ ᮧ 䠩
          㦥   (..   䠩   ),
            ⮣ 䠩 ⠭  0  १.

          
          ᥬ  IBM PC.  17.                            3


              砥  訡  ⠭ 䫠
          CF  1   頥  ॣ AX  :  03, 04  05
          (.⠡.17.1).   05  ᢨ⥫   ९
          ,        饣  䠩 ਡ⮬
          "⮫쪮 ⥭".   襭 樨 室 ᭠砫
          ஢  䫠  CF,  ⠪     ᮧ  䠩 
          ⠭  ॣ AX 䠩  0005,  
              訡 05 ( 㯠).
             
              䠩: .40
                 䠩 ᯮ 㭪  DOS .40. 
          ⮬  ॣ  BX    ⠭  䠩 ,
           ॣ CX -  ᫮ 뢠 ,    ॣ DX -
            뢮.   ᫥饬 ਬ ந室 
          256    OUTREC:
             
                 HANDLE1 DW   ?
                 OUTREC  DB   256 DUP (' ')
                         MOV  AH,40H         ;  
                         MOV  BX,HANDLE1     ;  
                         MOV  CX,256         ;  
                         LEA  DX,OUTREC      ;   뢮
                         INT  21H            ; 맮 DOS
                         JC   error2         ; ஢ઠ  訡
                         CMP  AX,256         ;   ᠭ?
                         JNE  error3
             
             ࠢ쭠  뢠       
           (256  ),  頥 䫠 CF  ⠭  ॣ
          AX ᫮ ⢨⥫쭮 ᠭ ⮢.  ᫨  ९
          ,   ᫮ ᠭ  ⮢   ⫨  
           ᫠.   砥 ࠢ쭮 樨  䫠 CF ⠭
            1,    ॣ AX   05 ( 㯠)
           06 (訡 䠩 ).
             ⨥ 䠩 : .3E
             ᫥ 襭  䠩 室 ⠭ 䠩
             ॣ BX  ,  ᯮ  㭪  DOS .3E,
            䠩.     뢠   ⠢訥 
                 ४    ⠡
           FAT.
                    MOV  AH,3EH         ;   ⨥ 䠩
                    MOV  BX,HANDLE1     ;  
                    INT  21H            ; 맮 DOS
             
              砥  訡   ॣ  AX  ⠭   06
          (ࠢ 䠩 ).
             
          :     .
          ------------------------------------------------------------
             ணࠬ,  ਢ    .17.2,  ᮧ  䠩  
          ,   ஥    짮⥫    .  
          ணࠬ    ᫥騥  ᭮  楤:
             

          
          ᥬ  IBM PC.  17.                            4


          C10CREA   ᯮ  㭪 .3C   ᮧ  䠩 
                    ࠭  䠩         
                     HANDLE.
          D10PROC   ਭ         頥 ஡
                             
                    .
          F10WRIT   뢠 䠩, ᯮ 㭪 .40.
          G10CLSE    襭 ࠡ⪨, ᯮ 㭪 .3E,
                    뢠 䠩  ⮣,  ⮡ ᮧ ࠢ
                     .
          
                  30  ⮢  蠥 
          ⠬:   ⪨ (.0DH)     ப (.
          0AH).   ࠧ      -  32 .
          ணࠬ ७   32-x ⮢ ,  
          䨪஢ .     " ⪨"
            "  ப",    ,  ᫨ ॡ 
          ஢ 䠩.  ணࠬ DOS SORT ॡ   ⮢
           樨  ᥩ.  襣 ਬ  SORT
           룫拉 ᫥騬 ࠧ:
             
                   SORT   B:<NAMEFILE.DAT   >NAMEFILE.SRT
             
               १  믮      䠩
          NAMEFILE.DAT   饩  ᫥⥫쭮   
          饭  䠩 NAMEFILE.SRT. ணࠬ, ਢ  .17.3
          믮  ⥭ ᥩ   䠩 NAMEFILE.SRT   뢮 
           ࠭.      : 1)  -
           ⪨   ப  祭     
          ⮫쪮   믮  ஢    㣨  
           饭.  2)      ६   (
              );   ᮡ 砥
          ஥ ⥫쭮 ணࠬ஢,    㤥 
            .17.4.
             
          ------------------------------------------------------------
          ------------------------------------------------------------
          .17.2. ᯮ짮 䠩   ᮧ 䠩.
          
            
          ------------------------------------------------------------
              ᫥ ࠧ   ॡ    
          ⥭ ᪮ 䠩  ७ ᨨ DOS.
             
             ⨥ 䠩: .3D
             ᫨  ணࠬ ॡ    ᪮  䠩, 
          ० 室   ,  ᯮ  㭪 .3D.
            ஢  ࠢ쭮  䠩    
          稥   ᪥.   ⨨ ॣ DX   ᮤঠ 
           室 ASCIIZ-ப,  ॣ AL -  㯠:
             
                 0   䠩 ⮫쪮  
                 1   䠩 ⮫쪮  뢮

          
          ᥬ  IBM PC.  17.                            5


                 2   䠩    뢮
             
          ⠫  ॣ  AL ᯮ   ࠧ 䠩
           DOS ᨨ 3.0    (.孨᪮  㪮⢮ 
          DOS).   ,     䠩 ᯮ
          㭪  ᮧ  (.3C),    㭪  䠩.
           ਢ ਬ  䠩  ⥭:
          
                    MOV  AH,3DH         ;   ⨥
                    MOV  AL,00          ; 쪮 ⥭
                    LEA  DX,PATHNM1     ; ப  ଠ ASCIIZ
                    INT  21H            ; 맮 DOS
                    JC   error4         ; 室  訡
                    MOV  HANDLE2,AX     ; ࠭   DW
             
             ᫨ 䠩   室   ,   
            ⠭      ࠢ  1, ਭ
          騩 ਡ,  뢠 䫠 CF   䠩
             ॣ AX.    ᯮ   쭥
          襬   ᫥ 権.
             ᫨ 䠩 ,    ⠭ 䫠 CF
             ॣ   AX  訡:  02, 04, 05  12 (.
          .17.1).    뢠 ஢  䫠  CF.   ᯥ譮
          ᮧ 䠩 ⥬  ⠭   ॣ AX 䠩
             0005,         訡 05
          ( 㯠).
             
             ⥭ 䠩: .3F
              ⥭ ᥩ 䠩 ᯮ  㭪  DOS .
          3F.   ⮬ 室  ⠭   ॣ BX 䠩
          ,  ॣ CX - ᫮ ⮢   ॣ DX -  
            .   ᫥饬  ਬ  ந室 뢠
          512-⮢ :
             
             HANDLE2     DW   ?
             INPREC      DB   512 DUP (' ')
                         MOV  AH,3FH         ;   ⥭
                         MOV  BX,HANDLE2     ;  
                         MOV  CX,512         ;  
                         LEA  DX,INPREC      ;   
                         INT  21H            ; 맮 DOS
                         JC   error5         ; ஢ઠ  訡
                         CMP  AX,00          ; ⠭ 0 ⮢?
                         JE   endfile
             
             ࠢ쭮 믮  뢠   ,
          뢠 䫠  CF    ⠭    ॣ  AX ᫮
          ⢨⥫쭮 ⠭ ⮢.  㫥 祭  ॣ
           AX 砥  ⥭ ᫥  䠩. 訡筠
            ⠭ 䫠  CF   頥   ॣ AX
            訡 05  ( 㯠)   06 (訡 䠩 
          ).


          
          ᥬ  IBM PC.  17.                            6


                 DOS  ࠭稢  ᫮  ६ 
          䠩,    ணࠬ,  ᯥ譮 ࠡ⠢   ᪮쪨
          䠩,  뢠 .
             
          :       
          ------------------------------------------------------------
               .17.3  ਢ ணࠬ,    ⠥ 䠩,
          ᮧ  ।饩  ணࠬ  (..17.2)    
          ஢  DOS SORT.    䠩 ᯮ
          㭪  .3D.  祭    १  䠩 
               HANDLE    ᯮ  ⥬   㭪樨
          .3F  ⥭ 䠩.
              ணࠬ  室 ७    
          ப,  ⠪     ᮤঠ    ᨬ "
          ⪨"  " ப".
             
          ASCII- (   ASCII)
          ------------------------------------------------------------
              ।  ਬ 뫨   樨 ᮧ 
          ⥭ 䠩.  ࠧ  ࠡ뢠 ASCII-
          䠩 (⥪⮢ 䠩),  ᮧ DOS   ।஬. 
          ⮣ 室  ࣠   ⠡ FAT,
           ⠪ ᯮᮡ       ᥪ ᪠, ᯮ㥬
          ⥬.  ⥬ DOS 뢠,  ਬ, ASM-䠩  
           ᮮ⢥⢨    ,  ᨬ ⠡
          樨 (.09),   ⪨ (.OD)     ப
          (.OA).     ᪮  DOS   뢠
          ஡,  室  ࠭  ।  ᨬ
          ⠡樨,  ஡, 室騥  ப ࠢ  ᨬ
          "  ⪨".  騩  ਬ    ᥬ
           ,    룫拉  ࠭:
             
                       <tab>MOV<tab>AH,09<return>
             
          ------------------------------------------------------------
          ------------------------------------------------------------
          .17.3. ᯮ짮 䠩    ⥭ 䠩.
          
              ⠪ ப ᮤন ASCII-䠩 㤥:
             
                       094D4F560941482C30390D0A
             
              ணࠬ TYPE   ।  䠩   뢮
            ࠭ ᨬ "⠡",  "  ⪨"   "
          ப" ⮬᪨ ࠢ .
             ᬮਬ  ணࠬ,  ਢ   .17.4, 
          ⠥  뢮  ࠭ 䠩  HANREAD.ASM (ਬ   .
          17.3)    ᥪࠬ.  ᫨ ணࠬ HANREAD  㦥   
          ஢७,       ᪮஢    䠩  
          .
          
          ------------------------------------------------------------
          ------------------------------------------------------------

          
          ᥬ  IBM PC.  17.                            7


                          .17.3. ⥭ ASCII-䠩.
          
             ணࠬ 믮  ᭮    㭪樨,    DOS
          TYPE,  ..  뢮    ࠭       ᨬ
          "  ⪨"     "  ப"  (CR/LE).  ப⪠
          ᮤন ࠭ (஫)  뢠  ஡.
          ᫨  ணࠬ  㤥 ।ᬮ७ ᯥ樠쭮 ஢ન
            ࠭,   뢮   ப 㤥 ⢫
                ⪮      ᨬ 
          ⠢ ࠢ   ப.   ࠢ쭮 ப⪨
          室  뢠 ப   ஫஢ ⨦
            ࠭.    ப ASCII-䠩   ६
          ,  ᫥ ।   ப ०, 祬
          뢮   ࠭.
             ᬠਢ ணࠬ 뢠   ᥪ 
            SECTOR. 楤 G10XFER ।  ⭮
              SECTOR      DISAREA,  㤠   
          뤠  ࠭.  㦥 ᨬ " ப",
          楤  뢮    ࠭  ᮤন  DISAREA,  
          "  ப".  (࠭  ᯫ  ਭ  ⠪  ᨬ
          ⠡樨  (.09)   ⮬᪨ ⠭  
          ᫥ ࠢ   8).
               ணࠬ  室  ஢    ᥪ  (
          뢠   ᫥饣)           뢮.  
          ⠭ ASCII-䠩, ⠪  ASM-䠩,  ப
           ⭮⥫쭮     ࠭஢   
           ன  ᨬ  CR/LF.  ⥪⮢  䠩,  ⠪ 
          EXE  OBJ,     ப  ⮬  ᬠਢ 
          ࠬ  ஢ ⨦    DISAREA 
            ࠧ襭.     ணࠬ  ।祭  
          뢮   ࠭  ⮫쪮  ASCII-䠩,     ஢
           客  直  ᨬ 䠩.
             楤 G10XFER 믮 ᫥饥:
          1.  樠   SECTOR.
          2.  樠   DISAREA.
          3.   ⨦   SECTOR  뢠 ᫥騩
              ᥪ.     砥      䠩,   蠥  ࠡ
              ணࠬ,  樠   SECTOR.
          4.   ⨦    DISAREA  ⠢ ᨬ
              CR/LF,  뢮  ப  ࠭   樠 
              DISAREA.
          5.  ९뢠 ᨬ   SECTOR   DISAREA.
          6.   ᨬ " 䠩"  (.1A) 蠥 ࠡ 
              ࠬ.
          7.    ᨬ "  ப"  (.OA)  뢮  ࠭
              ப  室   .2,   㣨 ᨬ   
              .3.
             
             ஡ 믮  ணࠬ  ⫠稪 DEBUG. 
             ᪠ ᬮ ᮤন    
               ,   DOS  ଠ . 
          襭    ணࠬ  ࣠  뢮     ࠭
            㪠 짮⥫   ⨯ 䠩.

          
          ᥬ  IBM PC.  17.                            8


             
                DOS
          ------------------------------------------------------------
             祭 ࠧ ᢮ ᪮ ࠭⢠:
             .36
              㭪  뤠 ଠ  ᪮  . 
          믮 㭪樨  室 㧨   ॣ DL 
          ᪮ (0 - ⥪騩 ᪮, 1 - A, 2 - B  ..):
             
                    MOV  AH,36H    ;  
                    MOV  DL,0      ; ⥪騩 ᪮
                    INT  21H       ; 맮 DOS
             
              㪠 ࠢ쭮   ᪮  
          頥  ॣ AX .FFFF,  ᫥騥 祭:
             
                     AX ᫮ ᥪ஢  
                     BX ᫮ 㯭 ஢
                     CX ᫮ ⮢  ᥪ
                     DX 饥 ᫮ ஢  ᪮
              ᨨ DOS  2.0   祭 ଠ樨  ᪮
              ᫥ ᯮ짮  㭪 .1B (
          ଠ  ⠡ FAT).
             
              䠩: .41
              㤠 䠩  ணࠬ ( ᪫祭 䠩 
          ਡ⮬  "⮫쪮  ⥭")  ᯮ  㭪 .41.
           ⮬   ॣ DX 室  㧨 ASCIIZ ப,
          ᮤঠ  㯠   䠩:
             
                    MOV  AH,41H         ;   㤠
                    LEA  DX,PATHNAM     ; ASCIIZ-ப
                    INT  21H            ; 맮 DOS
             
              砥 訡  ॣ  AX 頥   02 (䠩
           )  05 ( 㯠).
             
             ࠢ 䠩 㪠⥫: .42
             ⥬  DOS    䠩  㪠⥫,      
          ⨨ 䠩 ⠭    0    㢥稢   1
           ᫥⥫       뢠. 
          㯠     䠩     䠩
          㪠⥫   㭪樨  .42,     १
          אַ    䠩.
              ⠭ 䠩 㪠⥫  室  
          ॣ BX 䠩    ॣ஢   CX:DX ॡ
           ᬥ饭  .   ᬥ饭  65.535  ॣ CX
          ⠭ 0,    DX -  ᬥ饭.  ॣ AL 
           ⠭      ,    । 
           ᬥ饭:
             
          0  - ᬥ饭  砫 䠩.


          
          ᥬ  IBM PC.  17.                            9


          1  - ᬥ饭 ⥪饣 祭 䠩 㪠⥫, ஥
                   ,  砫 䠩.
          2  - ᬥ饭   䠩.   䠩 ( ᫥⥫쭮
               ᬥ饭     䠩)   ।, ⠭
               ॣ஢  CX:DX  0  ᯮ  2  ॣ
               AL.
          
              ᫥饬 ਬ ⠭ 䠩 㪠⥫ 
          ᬥ饭 1024   砫 䠩:
             
                    MOV  AH,42H         ; ⠭ 㪠⥫
                    MOV  AL,00          ;   砫 䠩
                    LEA  BX,HANDLE1     ; ⠭ 䠩 
                    MOV  CX,00          ;
                    MOV  DX,1024        ; 饭 1024 
                    INT  21H            ; 맮 DOS
                    JC   error
             
             ࠢ쭮 믮   뢠 䫠  CF  
          頥  㪠⥫  ॣ஢   DX:AX. ࠢ
            ⠭ 䫠 CF  1  頥  ॣ
           AX  01  (訡  )  06 (訡 䠩
          ).
             
             ஢ઠ   ਡ: .43
              ஢ન   䠩  ਡ   
           ᪠ ᯮ 㭪 .43H.  ⮬  ॣ
          DX   ⠭  ASCIIZ  ப.  ஢ન
          ਡ  ॣ  AL    ᮤঠ  00.   
          ਡ  ॣ AL    ᮤঠ 01,    ॣ CX -
            祭  ਡ.  騩  ਬ  ⠭
          ଠ ਡ:
             
                    MOV  AH,43H         ;   ⠭
                    MOV  AL,01          ;    ଠ쭮
                    MOV  CX,00          ;    ਡ
                    LEA  DX,PATHNM2     ; ASCIIZ-ப
                    INT  21H            ; 맮 DOS
             
              砥 ஢ન 㭪 頥  ⥪騩 ਡ 䠩
            ॣ  CX.   砥  㭪 ⠭
           ᮮ⢥饬     ਡ   ॣ
          CX.  ࠢ쭠   頥    ॣ  AX 
          訡 02, 03  05.
             
              ⥪饥 : .47
             ।  ⥪饣        ᪮
          ⢫   㭪樨 .47.   ⮬ 室
           ।   筮 , ⮡ ᮤ
            㯠 ᨬ쭮    㧨  ⮩
             ॣ DX.    DL    ᮤঠ 
          ᪮:  0  -  ⥪騩,  1 - A, 2 - B  ..  १


          
          ᥬ  IBM PC.  17.                           10


          믮   頥       ⥪饩
          ४ਨ  (    ᪮),  ਬ,  ᫥饬
          :
                                 ASSEMBLE\EXAMPLES
                                          
             㫥    (.00)    ⠢
             㯠.    ୥  ४ਨ 頥
          祭 ⮨ ⮫쪮       -  .00. 
          ࠧ   ⥪饥    㯠   
          䠩    .  ਬ    .17.5 
          ᯮ짮  㭪樨.
             
              䠩  蠡: .4E  .4F
              㭪樨  㭪 .  11  12 
          ᨨ DOS.  㭪 4E ᯮ  砫 ᪠   
          ,   㭪 4F -  த.  砫 ᪠
           ॣ DX 室 㧨  ASCIIZ-ப, ᮤ
          饩   㯠  蠡 ᪠.   ᪠ 
            ᥡ  ᨬ ?    *.   ॣ CX  
          祭  ਡ      樨  ⮢ (ଠ,
          , ⠭  ⥬).
             
                    MOV  AH,4EH         ;   砫 ᪠
                    MOV  CX,00H         ; ଠ ਡ
                    LEA  DX,PATHNM1     ; ASCIIZ-ப
                    INT  21H            ; 맮 DOS
             
             ᫨    室   䠩,  㤮⢮騩  蠡
          ᪠,    ⥪騩  DTA   FCB  ᫥饩
          ଠ樥:
             
             00 - १ࢨ஢ DOS  ᫥饣 ᪠
             21 - ਡ 䠩
             22 - ६ 䠩
             24 -  䠩
             26 - ࠧ 䠩: 襥 ᫮, ⥬ 襥 ᫮
             30 -   ⨯   13-⮢ ASCIIZ ப,
                  蠥 .00.
             
               砥  訡   ॣ AX 頥   02 (
          )   18 (  䠩).  த ᪠
          䠩  (᫥  㭪樨  .4E)  ᯮ  㭪 4F.
           ⨬ 㭪ﬨ  ᫥  ᮤন DTA.
             
                    MOV  AH,4FH         ;   த ᪠
                    INT  21H            ; 맮 DOS
             
             ⢥    ॣ AX -  18 ( 
          䠩).  ᬮ७ 㭪樨   ﭨ 䫠
          CF.
             
             २ 䠩: . 56


          
          ᥬ  IBM PC.  17.                           11


              २  䠩  ᯮ  㭪 .56.
            ⮬   ॣ DX    㦥   ASCIIZ-
          ப,  ᮤঠ饩  祭 ᪮,  㯠,
             ⨯  䠩,     ॣ  DI  ( ⢨⥫쭮
          ES:DI)  -    ASCIIZ-ப,  ᮤঠ饩   祭
          ᪮,   㯠,    ⨯ 䠩. ᫨  㪠뢠
             ᪮,          
          ப.   㯠   ࠧ, ⮬  
             ⮫쪮  २뢠 䠩,    ७
             㣮 .
             
               MOV  AH,56H         ;  २ 䠩
               LEA  DX,oldstring   ; DS:DX
               LEA  DI,newstring   ; ES:DI
               INT  21H            ; 맮 DOS
             
              砥 訡 ॣ AX 頥  03 ( 
            ), 05 ( 㯠?)  17 (ࠧ ᪮).
             㣨 㭪樨 DOS,  騥 ⭮襭  ᪮ 䠩,
           ᮧ  (.39), 㤠 
            (.3A),   ⥪饣  (.
          3B),  ࠢ  -뢮    ன  (.44),
          㡫஢  䠩     (.45),  ਭ㤨⥫쭮
          㡫஢ 䠩  (.46), 祭 ﭨ
          ஢ન ? (.54).
             
             
          ------------------------------------------------------------
          -   㭪樨 ७ ᨨ DOS   ASCIIZ-
             ப,   ᮤঠ    㯠   
             ⮬, ᮤঠ騬 .00.
          -  㭪樨 ᮧ    祭 䠩
             ,   ᯮ   ᫥饣 㯠 
             䠩.
          -   砥  訡   㭪樨 ⠭  䫠 CF 
               訡  ॣ AX.
          -   ࠢ,  㭪  ᮧ  ᯮ   
             䠩,   -  ⥭.
          -  ᫥ ⮣,    䠩  ᠭ   ,   室
               ⮣,  ⮡     뫨 ᥭ ᮮ
             騥 .
          
            
          ------------------------------------------------------------
          17.1.   祭      権 "䠩 
                 "  "訡 䠩 " ?
          17.2.  । ASCIIZ-ப      PATH1   䠩
                 CUST.LST  ᪮ C.
          17.3.    ।饣 䠩 (.17.2)     )
                 ।     CUSTHAN   䠩
                 , ) ᮧ 䠩, )  䠩  
                 CUSTOUT  (128  )   )  䠩. ᯥ
                 ஢  訡.

          
          ᥬ  IBM PC.  17.                           12


          17.4.   䠩 (.17.3)   )  䠩
                  )  ⥭ 䠩    CUSTIN. ᯥ 
                 ஫ 訡.
          17.5.      室  뢠  䠩, 
                   ⮫쪮  ⥭ ?
          17.6.   ணࠬ   .17.4  ⠪,  ⮡ 짮
                 ⥫           䠩, 
                 室  뤠    ࠭. ᯥ 
                   ᫠ ᮢ   襭 ணࠬ ⮫쪮
                   ⮬ ,  ..  ⮬   
                 Return.
           










































          
