          ᥬ  IBM PC.  8                            172


          
           8
          ------------------------------------------------------------
          
          ࠭ 樨 I: ᭮ ᢮⢠
          
          : ᭨ ॡ  뢮 ଠ樨  ࠭, 
          ⠪     .
          
          
          ------------------------------------------------------------
          
              ।      ணࠬ,   
            o।﫨  ࠭   (।⢥
          )  樠஢    ணࠬ.
          ᫮  ࠪ᪨ ਬ ⠪ ணࠬ   ⢨⥫
            .  設c⢮  ணࠬ  ॡ    
          ,  ᪠    ᯥ稢  뢮  
          㤮  ଠ     ࠭,   ਭ    .  ,
          ।祭   뢮   ࠭     ,
           ASCII ଠ.
               믮    뢮  ᯮ  INT
          (뢠).   ࠧ  ॡ  㪠
          ⥬    ⢨  (     뢮)       
          ன⢥  室  믮.     뢠
          ᭮ ॡ  뢮  ଠ樨  ࠭   
            .
               室 ࠭     樨 
          믮  ᯮ    INT  10H,     ।
          ࠢ ।⢥  BIOS.   믮 
           ᫮ 権   뢠  ᮪
          ஢ INT 21H,  ஥ ᭠砫 । ࠢ   DOS.
          ਬ,      ॡ 
           ᨬ,  ஢  ᨬ쭮 ᫮ ᨬ
            ஢    ᨬ  Return.   p뢠  DOS  INT  21H
          믮     ⥫  ᫥  ⥬
          ⮬᪨ । ࠢ  BIOS.
             ਠ      室       ஬
          (୮-,  BW),  ⠪     梥  ஢. 
            9    10  ਢ  ਠ    ࠢ  
          ᮢ襭묨 ࠭   ᯮ짮 梥.
             
           : INT
          ------------------------------------------------------------
          
               INT  뢠  ࠡ   ணࠬ,  ।
          ࠢ  DOS  BIOS  । ⢨  ⥬
          頥 ࠢ  ࢠ ணࠬ  த
          ࠡ⪨.       뢠   ᯮ  
          믮  権       뢮.     室  
          ணࠬ    ࠡ   뢠       ᫥饣
            INT 믮 ᫥騥 ⢨:
             

          
          ᥬ  IBM PC.  8                            173


              㬥蠥 㪠⥫ ⥪  2    設
               ⥪ ᮤন 䫠 ॣ;
              頥 䫠 TF  IF;
              㬥蠥 㪠⥫ ⥪  2   ᮤন
               ॣ CS  ⥪;
              㬥蠥 㪠⥫ ⥪  2    ⥪
               祭  㪠⥫;
              ᯥ稢 믮 室 ⢨;
              ⠭  ⥪ 祭 ॣ  頥
               ࠢ  ࢠ ணࠬ  , ᫥
               ᫥ INT.
          
               믮   ⮬᪨. 
             ।  ᥣ ⥪ 筮  訬 
             祭 ॣ஢.
                  ᬮਬ   ⨯ 뢠: 
          BIOS INT 10H   DOS INT 21H    뢮    ࠭ 
            .   ᫥ ਬ  ᨬ 
          ॡ ᯮ  INT 10H ⠪  INT 21H.
             
           
          ------------------------------------------------------------
          
             ࠭  ।⠢    㬥୮ ࠭⢠ 
          㥬묨 ﬨ        ⠭
           .   ,  ਬ,  25 ப
          (㬥㥬  0   24)   80  ⮫殢 (㬥㥬  0 
          79).     ᫥饩  ⠡   ਢ    ਬ
             ࠭:
             
             --------------------------------------------------------
                                    . ଠ         .ଠ
                                   --------------      --------------
                          ப ⮫      ப ⮫
             --------------------------------------------------------
             孨  㣮      00      00          00      00
             孨 ࠢ 㣮     00      79          00      4F
              ࠭            12     39/40        00     27/28
               㣮       24      00          18      00
              ࠢ 㣮      24      79          18      4F
             --------------------------------------------------------
             
              INT 10H 砥  ᥡ ⠭   
              ࠭.    ਢ  ਬ ⠭
            5- ப  12- ⮫:
             
                         MOV  AH,02     ;  ⠭ 
                         MOV  BH,00     ;࠭ 0
                         MOV  DH,05     ;ப 05
                         MOV  DL,12     ;⮫ 12
                         INT  10H       ;। ࠢ  BIOS
             


          
          ᥬ  IBM PC.  8                            174


          祭 02  ॣ AH 㪠뢠  INT 10H  믮
           樨 ⠭ .  祭 ப  ⮫
             ॣ DX,    ࠭  ( ࠭) 
          ॣ BH (筮 0). ন 㣨 ॣ஢ 
          .   ⠭ ப  ⮫   ⠪ ᯮ짮
             MOV c ।⢥ . 祭:
          
                         MOV  DX,050CH  ;ப 5, ⮫ 12
          
           
          ------------------------------------------------------------
          
                  ࠭     ᬥ
             १ ப稢  ("஫")  ९ᠭ
           ⮬     㣨  ᠬ    . 
          ணࠬ 稭 c 믮, ࠭   饭.
          頥  ࠭  稭    樨 
          稢     㣮  樨    訬 ஬.
          砫쭮 祭 ப  ⮫    ॣ DX,
          祭 07 -  ॣ BH  0600H  AX.  ᫥饬 ਬ
          믮 ⪠ ᥣ ࠭:
             
                    MOV  AX,0600H  ;AH 06 (ப⪠)
                                   ;AL 00 ( ࠭)
                    MOV  BH,07     ;ଠ ਡ (୮/)
                    MOV  CX,0000   ;  
                    MOV  DX,184FH  ; ࠢ 
                    INT  10H       ;। ࠢ  BIOS
             
             祭 06   ॣ  AH 㪠뢠   INT 10H 
          믮 樨  ⪨  ࠭.     頥
          ࠭  ஡;    ᫥饩    ஫ (ப⪠)
          㤥  ᬮ७  ஡.  ᫨    訡 ⠭
            ࠢ   ,  祬 .  184F,  ⪠
          ३   砫 ࠭  筮  
          樨 ஡.   ஬ ࠭   뢠
          - ⭮⥩,    梥 ஢
            쥧 訡.
             
             :   DOS
          ------------------------------------------------------------
          
             筮 ணࠬ  뤠  ࠭ ᮮ饭  
          襭   㦥 訡, ⮡ࠧ   
              祭 㪠  짮⥫. ᬮਬ
          ᭠砫 ⮤, ਬ塞   ᨨ DOS,  ᫥
           p   ७  ⮤,  
          DOS ᨨ  2.0.  樨    DOS  ࠡ  
          ,    㪮⢥  DOS  ४ ਬ
          ७        ࠧࠡ⮪.   
          ᨨ DOS  뢮  ࠭   ᫮,  
                ᯮ짮,  ஥
           ஢ઠ.

          
          ᥬ  IBM PC.  8                            175


             
            :   DOS
          ------------------------------------------------------------
          
             뢮  ࠭    ᨨ  DOS ॡ ।
          ⥪⮢ ᮮ饭   ,  ⠭  ॣ
          AH 祭 09  (맮 㭪樨 DOS)   㪠  DOS
          INT 21H.      믮  樨   ᮮ饭
          ।  o࠭⥫ ($),    :
             
             NAMPRMP     DB   ' 㯠⥫?','$'
                         .
                         .
                         MOV  AH,09          ; 뢮  ࠭
                         LEA  DX,NAMPRMP     ;㧪  ᮮ.
                         INT  21H            ;맮 DOS
             
           ࠭⥫ "$"  ஢ ।⢥ ᫥
          c쭮 ப (     ਬ),  ப:
          '  㯠⥫?$',      ᫥饬    DB  '$'.
          ᯮ    ,   뢥  ࠭ ᨬ
           "$".  ஬ ⮣,  ᫨   㤥 ⢮
                ப,      ࠭    뢮 
          ᫥騥 ᨬ,   "$"    .
              LEA 㦠   NAMPRMP   ॣ DX
           ।   DOS  뢮  ଠ樨.  
          NAMPRMP,  㦠   DX   LEA,   o⭮
          ⥫,  ⮬   ᫥  ᮫⭮  
          DOS ᪫뢠 祭 ॣ஢ DS  DX (DS:DX).
             
          :       ASCII
          ------------------------------------------------------------
          
             設⢮  256   ASCII  ᨬ쭮 ।⠢
          ,    뢥  ࠭. .  00  FF 
           ᨬ   뢮   ࠭    ஡, 
          ᨬ ஡   ASCII .  20.
              .  8.1   COM-ணࠬ,   뢮 
          ࠭    ᨬ  ASCII.  ணࠬ 뢠
           楤;  B10CLR,  C10SET  D10DISP.  楤 B10CLR
          頥 ࠭,   楤  C10SET  ⠭   
            00,00.  楤 D10DISP 뢮 ᮤন 
          CTR,  ஥  砫 樠஢ 祭 00  ⥬
          y稢    1      뢮  ࠭,   
          ⨣ . 祭 FF.
          
          ------------------------------------------------------------
          ------------------------------------------------------------
               . 8.1. 뢮  ࠭  ᨬ  ASCII
             
               ᨬ   뢮  ࠭  ஬ ⮣
              .   08     .  0D    ᯥ樠묨
          ࠢ騬  c,       ਢ    ६饭

          
          ᥬ  IBM PC.  8                            176


            㣨 ࠢ騬 ⢨.  : 
          ணࠬ (.8.1), 믮 ᥬ஢,  
          ८ࠧ  COM-䠩.   ᪠ ணࠬ  
          , ਬ, :ASCII.COM.
             ࢠ 뢥 ப 稭  ஡쭮 ᨬ
          (.00),    "론 "  (.  01  02)  
           ᨬ (.03,  04   05).  07 뤠 㪮
            ᨣ.   06   ⮡ࠧ  ᨬ
          "",   ࠢ騥 ᨬ  .08  0D  .
           0D  "⮬ ⪨"  ਢ  室 
           (᫥)ப.  .0E - ।⠢  
          몠쭮 .  ᫥ . 7F  ᪨
          .
               ணࠬ  室 ࠢ ᨬ.
           ਢ ਬ ࠣ ணࠬ, 騩 
             ᨬ      .    08       0D.      
          ᯥਬ஢,   o室  ⮫쪮,   ᪠,  .  08
          (  ᨬ)  0D ( ⪨):
             
                         CMP  CTR,08H        ; 祬 08?
                         JB   D30            ;  - ਭ
                         CMP  CTR,0DH        ; /ࠢ 0D?
                         JBE  D40            ;  - 
               D30:
                         MOV  AH,40H         ;뢮 ᨬ  < 08
                         ...                 ;               > 0D
                         INT  21H
               D40:
                         INC  CTR
             
             :   DOS
          ------------------------------------------------------------
          
             楤      ,  祬 뢮 
          ࠭.   ,  ᯮ饣  DOS,  
          ॡ  c᪠ ࠬ஢, ᮤঠ饣 , 
          室   믮    INT.  -, 
           ।  ᨬ쭠      ⥪. 
          室   ।०  짮⥫  㪮 ᨣ
          , ᫨ ࠭ ᫨誮  ⥪; ᨬ, ॢ騥
          ᨬ      ਭ.  -,    ᯨ᪥
          ࠬ஢      ।  ,  㤠  
          頥 ⢨⥫   ⥪  .
              ਢ ਬ,   ஬ । ᯨ᮪ ࠬ
          ஢   .  LABEL ।⠢ ᮡ ४⨢ 
          ਡ⮬  BYTE.      ᮤন  ᨬ 
           .    ⮢ ,  
          ᨬ쭮  祭  -  .  FF  255. ன 
          室  DOS  ᥭ      ⢨⥫쭮 ᫠
           ᨬ.  쨬 ⮬ 稭 , ஥
          㤥 ᮤঠ  ᨬ.
             
             NAMEPAR     LABEL     BYTE           ;᮪ ࠬ஢:

          
          ᥬ  IBM PC.  8                            177


             MAXLEN      DB        20             ; ᨬ쭠 
             ACTLEN      DB        ?              ; 쭠 
             NAMEFLD     DB        20 DUP (' ')   ;  ᨬ
             
                ᯨ᪥  ࠬ஢ ४⨢  LABEL  
          ,   NAMEPAR  MAXLEN 㪠뢠      a
          .  ࠭ MASM  । ᯨ᪠ ࠬ஢
              ᯮ짮 ⠪ ४⨢ STRUC.
          ,   裡  ⥬,   뫪    , ।
          , ॡ ᯥ樠쭮 樨, ন c 
          ᬮ७  ⥬   24 "४⨢ ᥬ".
                   室     ॣ AH
           㭪樨 -  10 (. 0AH), 㧨  ᯨ᪠ 
          ஢ (NAMEPAR   襬 ਬ)   ॣ DX   믮
          INT 21H:
             
               MOV  AH,0AH         ; 㭪樨 
               LEA  DX,NAMEPAR     ;㧨  ᯨ᪠ ࠬ஢
               INT  21H            ;맢 DOS
             
              INT   짮⥫     
           ⥪,  ஢  ⮬,  ⮡ ᫮  c
            ॢ蠫 ᨬ쭮 祭, 㪠  ᯨ᪥
          ࠬ஢  (20   襬 ਬ).   㪠  
          짮⥫      Return.    ⮩  
          (.  0D)  ⠪       (NAMEFLD  襬
          ਬ).   ᫨,  ਬ,  짮⥫      BROWN
          (Return),  c᮪ ࠬ஢ 㤥 ᮤঠ ଠ:
             
             .:  20 5  R O W N #         ...
             .: 140542524F574E0D20202020 ...
             
           ன    ᯨ᪠ ࠬ஢ (ACTLEN   襬 ਬ)
                  -  05.   Return
          室   NAMEFLD +5.   #  ᯮ짮 
            樨   ,  ⠪    .  0D   
          ⮡ࠦ ᨬ.  ᪮  ᨬ쭠     20
          ᨬ 砥 .0D,  ⢨⥫쭠  
          ⥪   ⮫쪮 19 ᨬ.
          
          :    
          ------------------------------------------------------------
          
             EXE-ணࠬ,  ਢ  . 8.2, 訢 
          ,  ⥬ ⮡ࠦ  ।  ࠭    
          砥 㪮 ᨣ. ணࠬ த 訢 
          ⮡ࠦ ,  짮⥫   Return  ⢥
           । . ᬮਬ ,  짮⥫
            TED SMITH:
             
          ------------------------------------------------------------
          ------------------------------------------------------------
                    . 8.2.   ⮡ࠦ 

          
          ᥬ  IBM PC.  8                            178


          
             1.   09  2 稬 4, 
             2. ⥬  祭  40, 稬 36
             
              SHR  楤 E10CENT ᤢ  09  o
           ࠢ,  믮 ⠪ ࠧ     2. 祭
           00001001  室  00000100.   NEG  
          +4    -4.    ADD  ਡ  祭  40, 
           ॣ DL  砫쭮  ⮫ -  36.  ⠭
              ப  12   ⮫ 36   㤥 뢥 
          ࠭  ᫥饬 :
             
                    ப 12:     TED SMITH
                                      
                    ⮫:       36  40
             
              楤 E10CODE   ,  ⠭
            c 㪮  ᨣ (07)     ।
          ⢥ ᫥ :
             
                         MOV  NAMEFLD[BX],07
             
          ।  ⠭  ॣ  BX 祭
          ,   MOV ⥬,    ॣ BX 
            NAMEFLD,  뫠  07.  ਬ,  
           05   07 㤥 饭   NAMEFLD+05 (
          祭  Return). ᫥   楤 E10CODE
          ⠭ ࠭⥫ "$" ᫥  07.  ࠧ,
           楤 F10CENT 뢮  ࠭ ,   p
           ⠪ 㪮 ᨣ.
          
              ⢥ ᨬ Return
             
                 ,  ॢ饣      ᨬ쭮
          祭,  㪠  ᯨ᪥ ࠬ஢,  㪮
          ᨣ  ⥬  o  ⮫쪮  ᨬ Return. ᫨
              ,   ⮫쪮    Return, 
          ⥬  ਬ   y⠭   ᯨ᪥  ࠬ஢ 㫥
           ᫥騬 ࠧ:
             
                    ᮪ ࠬ஢ (.):    14000D...
             
           祭    짮⥫   
            Return  ⢥  ।     .
          ணp ।    㫥 .
          
              ᨬ Return
             
               祭   ᯮ짮    ᠬ ࠧ
          楫,   ਬ:        ᮮ饭,  ࠭  
          ⠡,      .    ⮬,  ,  
          室    ᨬ  Return  (.0D)   
          NAMEFLD   ᨬ ஡ (.20).   NAMELEN ᮤন

          
          ᥬ  IBM PC.  8                            179


          ⢨⥫   ⭮c⥫    0D. ᫨,
          ਬ,  NAMELEN ᮤন  05,    0D ࠢ
          NAMEFLD+5.             ॣ  BX  
          ᭮ 樨   NAMEFLD:
             
                    MOV  BH,00               ;⠭  ॣ BX
                    MOV  BL,NAMELEN          ;    祭 0005
                    MOV  NAMEFLD[BX],20H     ; 0D  ஡
             
              MOV    ᨬ  ஡  (.20) 
          ,  o।  ࠭:    NAMEFLD
           ᮤন ॣ BX, .. NAMEFLD+5.
          
             ⪠  
             
              ᨬ   ।饥  ᮤন 
               ⠬,   㣨 ᨬ    .
          ᬮਬ ᫥騥  ᯥ  :
             
                               NAMEPAR (.)
             1. BROWN    140542524F574E0D202020 ... 20
             2. HAMILTON 140848414D494C544F4E0D ... 20
             3. ADAMS    14054144414D530D4F4E0D ... 20
             
           HAMILTON   ⪮  BROWN.  , ⠪ 
           ADAMS     HAMILTON,       ⮫쪮
          HAMIL.   Return   ᨬ T.  ⠫ 㪢 - ON
          o  ᫥  ADAMS.    ⪨    NAMEFLD 
           ।   㦨 ᫥ ணࠬ:
          
                    MOV  CX,20               ;⠭ 20 横
                    MOV  SI,0000             ;砫쭠  
               B30:
                    MOV  NAMEFLD[si],20H     ;᫠  ஡
                    INC  SI                  ;  
                    LOOP B30                 ;20 横
          
           ॣ SI  ᯮ짮 DI  BX.  䥪
          ⨢  ᯮᮡ ⪨ ,  ।騩 뫪 ᫮
             ஡,  ॡ  ⮫쪮    横. ,
           ⮣     NAMEFLD ।   DB (⮢),
          室       뫪, ।⢮
          ࠭  WORD,   a  ⠪  ᯮ짮   ࠭  PTR
          (㪠⥫),   :
          
                    MOV  CX,10               ;⠭ 10 横
                    LEA  SI,NAMEFLD          ;砫 
               B30:
                    MOV  WORD PTR[SI],2020H  ;᫠  ஡
                    INC  SI                  ; 
                    INC  SI                  ;  ᫥饣 ᫮
                    LOOP B30                 ;10 横
          

          
          ᥬ  IBM PC.  8                            180


           MOV  ⪥ B30  砥 뫪 ᫮  
          ஡  ,  室饬  ॣ SI.  ᫥
          ਬp ᯮ  LEA   樠樨 ॣ
          SI  ᪮쪮  ᯮᮡ   MOV   ⪥  30, ⠪
            ஢, ਬ, ᫥ :
          
                    MOV  WORD PTR[NAMEFLD],2020H  ;ࠢ쭮
          
             ⪠  室  蠥  ஡   ⪨
          ,  묨 ᫥ ।騥 .   䥪
          ⨢ cᮡ ।  ⮫쪮   , 
          ᯮ ᫥  .
          
             :   DOS
          ------------------------------------------------------------
          
             ᬮਬ ⥯  ७  ,   
          DOS 2.0  (ॠ  ⨫  樮 ⥬ UNIX).
          ᫨  ᯮ    DOS,    ᬮ
          믮 ਬ    ࠧ. ७ 
              䠩  (file  handle),  y⠭
             ॣ BX,   ॡ 믮 
          /뢮.     ᫥騥  ⠭  䠩
          :
             
                    0     (筮  ) CON
                    1    뢮 (筮  ࠭) CON
                    2    뢮  訡 ( ࠭) CON
                    3    /뢮  譥 ன⢮ AUX
                    4    뢮   LPT1  PRN
             
             뢠 DOS  /뢮  -  INT  21H, 室
          㭪 訢 १ ॣ AH: .3F -  ,
          .40  -  뢮.  ॣ CX  ᫮  
          /뢮,   ॣ DX -   /뢮.
              १  ᯥ譮 믮  樨 /뢮
          頥 䫠 ७ (CF)    ॣ AX ⠭
          ⢨⥫쭮  ᫮  ,      樨.  
          ᯥ譮 o樨 ⠭ 䫠 CF,   訡 (
           砥 6)    ॣ  AX. ᪮ ॣ
          AX   ᮤঠ   ,  ⠪    訡, 
          ⢥ ᯮᮡ  ।  稥 訡  - ஢
          䫠 CF,   訡 ⥭    뢮   ࠭
          -   ࠩ  ।.   oࠧ ᯮ
          䠩         ᪮   䠩,     o訡
          /뢮  .
              ᯮ짮  㭪樨  ७ࠢ -
          뢮  㣨 ன⢠,   ᮡ  
          ᬠp.
             
            :   DOS
          ------------------------------------------------------------
          

          
          ᥬ  IBM PC.  8                            181


             騥    뢮  ࠭ 
          ७ ᨨ DOS:
             
               DISAREA   DB   20 DUP(' ')    ; 
                         ...
                         MOV  AH,40H         ;  뢮
                         MOV  BX,01          ;뢮 ன⢮
                         MOV  CX,20          ;ᨬ쭮 ᫮ 
                         LEA  DX,DISAREA     ;  
                         INT  21H            ;맮 DOS
             
              LEA 㦠    ॣ  DX    DISAREA 
           DOS  ଠ, ।祭 
          뢮.  १ ᯥ譮 樨 䫠 ७ 頥
            (   ஢),    ॣ AX ⠭
          ᫮  뢥  ᨬ.  訡   樨 
          ந,  ᫨ y⠭  ࠢ  䠩 . 
          ⮬ 砥 㤥 ⠭ 䫠 CF    訡 ( 
          砥  6)     ॣ  AX.  ᪮  ॣ  AX  
          ᮤঠ  ,    訡,  ⢥ ᯮᮡ
          । ﭨ 訡 - ஢ 䫠 CF.
             
             ࠦ: 뢮  ࠭
             
             ᯮ㥬  ⫠稪  DEBUG   ஢ન ७
          䥪⮢ 뢠. 㧨 DEBUG  ᫥ 뢮  ࠭
          ਣ襭  A 100    ᥬ  (
          設  )    p  100.    ,   DEBUG
          ।,      ᫠     ᭠筮
          ଠ.
             
                    100  MOV  AH,40
                    102  MOV  BX,01
                    105  MOV  CX,     (  襣 )
                    108  MOV  DX,10E
                    10B  INT  21
                    10D  RET
                    10E  DB   ' '
             
          ணࠬ  ⠭  ॣ  AH      뢮 
          ⠭ .  祭 10F  ॣ DX -   DB,
          ᮤঠ饩     ணࠬ.
                  ,     ࠧ Return.
             U (U  100,10D)  ᥬ ணࠬ
           ஢ન.  ⥬ ᯮ  R  T  ஢
            믮.    믮    INT  21H ⫠稪
          ३  BIOS,  ⮬  ⨦   10B 
            GO  (G  10D)   室    RET.  
          㤥 뢥    ࠭.     Q  ୨ 
          DOS.
             
            :  DOS
          ------------------------------------------------------------

          
          ᥬ  IBM PC.  8                            182


          
               ਢ   ,  騥  ᯮ짮
          㭪樨     ७ ᨨ DOS:
             
               INAREA    DB   20 DUP (' ')   ; 
                         MOV  AH,3FH         ;  
                         MOV  BX,00          ;  
                         MOV  CX,20          ;ᨬ   
                         LEA  DX,INAREA      ;  
                         INT  21H            ;맮 DOS
             
               LEA  㦠  ⭮⥫     INAREA  
          ॣ DX.  INT ,  짮⥫  
          c   ,     ஢ ॢ蠥   ᫮
           ᨬ ᨬ쭮 祭  ॣ CX (20 
          ਢ ਬ).  ⨥  Return ( . 0D)
          㪠뢠  襭 .  ਬ, ᫥  ⥪
          "PC Users Group" INAREA 㤥 ᮤঠ:
             
                         PC Users Group, .0D, .0A
             
          ᫥   ⥪ ।⢥ ᫥  ᨬ 
           ⪨ (. 0D),   ,  ᨬ 
          ப  (.  0A),      .   ᨫ 
          ᮡ  ᨬ쭮  ᫮ ᨬ    ࠧ 
             ।ᬠp     ᨬ. ᫨
          㤥   c    ᨬ쭮 祭, 
                묨  ᨬ  ࠭ ०
          祭.
              १ ᯥ譮 樨 㤥 饭 䫠  CF (
            ஢)    ॣ  AX  㤥 ⠭ ᫮
          ,   .  ।饬 ਬ  ᫮
          㤥 ࠢ 14   2   ॢ ⪨   ப,
          ..16.  ⢥騬 ࠧ ணࠬ   ।
          ⢨⥫쭮 ᫮   ᨬ.     ᢮
          ⢮ 쬠  ਢ쭮   ⢥⮢ ⨯  YES    NO, 
              ⢥⮢   p  , ⠪,
          ਬ,  .
             訡    ,  ᫨ । ࠢ
            䠩.   ⮬ 砥 㤥 ⠭ 䫠 CF  
          ॣ AX 㤥 饭  訡 (6   砥). 
           ॣ AX  ᮤঠ      ,
            訡,   ⢥ ᯮᮡ  । 
          訡 - ஢ઠ 䫠 CF.
             ᫨  ⥪,  ॢ蠥 ᨬ ,
          y⠭    ॣ  CX,      ਭ  
          ᨬ. ᬮਬ ,  ॣ CX ᮤন 08,
          짮⥫    ᨬ  "PC  Exchange".   १
           ᥬ  ᨬ  "PC Excha"     
              ⪨    ப.    ॣ AX
          㤥  ⠭   08.      INT 㤥
          ਭ    ,    ᮡ⢥ ,
          ᪮ ⠬  ⠫ ।騥 .  ࠧ,

          
          ᥬ  IBM PC.  8                            183


              ਭ ᨬ "ng", ᨬ ॢ
          ⪨  ᨬ  ப,   ॣ AX  㤥 ⠭
           祭 05.  樨    ଠ
          묨  䫠 CF 㤥 饭.
             
              INT:      PC Excha       AX = 08
             ன INT:      ng,0D,0A      AX = 05
             
             ணࠬ     ।  䠪     祭
          ⥪, ᫨ )  ॣ AX  祭 , 祬
           ॣ  CX   )  ᫨  ᮤন  AX   CX ࠢ, 
          ᫥  ᨬ    - 0D  0A.
             ஥  DOS ஢ન    㭪樨  0AH     
              ।⢠.   롮  ᯮ
            ணࠬ  ।⥫.
             
             ࠦ:   
             
             믮  ࠦ  ஬   ᫥ 
           c     ⫠稪  DEBUG. ।
           ணࠬ        12  ᨬ, 
          ᨬ  ⪨      ப.  㧨  DEBUG 
          ᫥  뢮  ࠭ ਣ襭  A  100   
          ᥬ ,  稭 c  100.  , 
          DEBUG    ।,           ᫠       
          ᭠筮 ଠ.
             
                         100  MOV  AH,3F
                         102  MOV  BX,00
                         105  MOV  CX,0C
                         108  MOV  DX,10F
                         10B  INT  21
                         10D  JMP  100
                         10F  DB   ' '
             
             ணࠬ ⠭ ॣ  AH  BX    
           c ,    ᨬ      
           CX  㦠  ॣ DX 祭 10F -   DB
            ணࠬ.        
          ᨬ.
                   ,    ࠧ Return.
               U  100,108  믮 ᥬ஢
          ணࠬ  ஢ન.  ⥬ ᯮ  R  T 
          ஢      MOV.  ⠭   
          10B,    G 10D  믮   INT  (室 
          BIOS    ᫥).   ⫠稪   ,
          蠥 襩  Return.  ஢ ᮤন ॣ
          AX,  ﭨ 䫠 CF   ᯮ  D  10F, ᬮ
                  .    襭  ࠡ
            Q.
             
             ,   
              

          
          ᥬ  IBM PC.  8                            184


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