          ᥬ  IBM PC.  12                           262


          
           12
          ------------------------------------------------------------
          
          䬥᪨ 樨 I: ࠡ⪠  
          
          :     ᢥ      ᫮,  ⠭,
          㬭    .
          
          
          ------------------------------------------------------------
          
             ᬮ  ,    ਢ몫   筮 䬥⨪
          ( 10),  ࠡ⠥ ⮫쪮  筮  䬥⨪
          (  2).  ஬  ⮣,    ࠭祭, 뢠
          16-⮢묨 ॣࠬ, 訥 稭 ॡ ᯥ樠쭮
          ࠡ⪨.
                    ᢥ       ᫮,
          ⠭,  㬭        
          .   ਢ  ਬ஢  ।० 
          ࠧ  誠    ஬稢  ᫥⥫  
          ய.   ᫥饩     樨
          ८ࠧ    묨  묨    ASCII  .
          
            
          ------------------------------------------------------------
             
              ADD   SUB 믮 ᫮   ⠭ ⮢
           ᫮,  ᮤঠ  . ⠭ 믮
             ⮤ ᫮    : 
          ண  ࠭  ⠭   祭   
          ਡ   1,    ⥬  நCX  ᫮    
          ࠭.   ᥬ, ஬ ࢮ 蠣, 樨 ᫮ 
          ⠭ .
              .  12.1  ।⠢ ਬ   ADD    SUB,
          ࠡ뢠騥         ᫮.     楤  B10ADD
          ᯮ  ADD  ᫮ ⮢,    楤
          C10SUB    SUB ⠥ ᫮.  ਬ 뢠 
            権:
                    ᫮/⠭ ॣ-ॣ;
                    ᫮/⠭ -ॣ;
                    ᫮/⠭ ॣ-;
                    ᫮/⠭ ॣ-.祭;
                    ᫮/⠭ -.祭.
          
          ------------------------------------------------------------
          ------------------------------------------------------------
                    . 12.1 ਬ  ADD  SUB.
             
             ᪮ אַ  樨  -   ,
            o  믮  १  ॣ.    ᫥饬
          ਬ   ᮤন ᫮  WORDB  ਡ ᮤন
          ᫮ WORDA, ᠭ  DW:

          
          ᥬ  IBM PC.  12                           263


             
                              MOV  AX,WORDA
                              ADD  AX,WORDB
                              MOV  WORDB,AX
             
             ९
             
             ᠩ ९  䬥᪨  . 
           ᮤন    ᥬ  ,  .. 祭
           -128    +127.    䬥᪮ 樨 
            ॢ   ⮢  ॣ. ਬ,
          १ ᫮   ॣ AL,  ॢ騩  ,
          ⮬᪨   室  ॣ  AH.  ।, 
          ॣ AL ᮤন .60, ⮣ १ 
             
                              ADD  AL,20H
          
              AL  㬬  -   .80.      ⠪
          ⠭ 䫠 ९    䫠  ﭨ
          "⥫쭮".  稭 砥  ⮬,   .80 
          筮  1000  0000   ⥫  ᫮. .. 
          १,   +128,   稬 -128.    ॣ
          AL ᫨誮   ⠪ 樨   ᫥ ᯮ짮
          ॣ஬ AX.   ᫥饬 ਬ  CBW (Convert Byte
          to Word -  ८ࠧ   ᫮) ८ࠧ .60 
          ॣ  AL  .0060   ॣ AX,  ।  ⮬
            (0)  १ ॣ AH.   ADD  
          ⥯   ॣ  AX ࠢ १:  .0080, 
          +128:
             
                         CBW            ;७ AL  AX
                         ADD  AX,20H    ;ਡ  AX
             
                 ᫮  ⠪ ࠭祭:   
            15   ,   ᮮ⢥ 祭  -32768
           +32767.  ᬮਬ      ࠡ뢠 ᫠,
          ॢ騥  ।.
             
             ᫮ ᫮
             
             ᨬ쭮  祭   ॣ +32767 ࠭
          稢     믮 䬥᪨
          権.  ᬮਬ   ᯮᮡ 믮 䬥᪨
          権.  ᯮᮡ -  ,  ᯥ祭, ன
          - ᫮,   騩 ࠪ.
          
          ------------------------------------------------------------
          ------------------------------------------------------------
                    . 12.2.   ᫮.
          




          
          ᥬ  IBM PC.  12                           264


              .12.2 楤 D10DWD  ⮩ ᯮᮡ
          ᫮  ᮤন    ᫮  (WORD1A   WORD1B) 
          ᮤন ன  ᫮  (WORD2A  WORD2B)   ࠭
          㬬    쥩    ᫮  (WORD3A    WORD3B).  砫
          믮 ᫮ ࠢ ᫮:
             
                              WORD1B          BC62
                              WORD2B          553A
                              㬬:         1119C
             
             㬬   -   .1119C  ॢ蠥    ॣ  AX.
          ९ 뢠  ⠭ 䫠 ७    1. ⥬
          믮 ᫮  ᫮,     砥, 
            ADD ᯮ   ᫮   ७ᮬ ADC
          (ADd  with  Carry).    ᪫뢠   祭, 
          ᫨ 䫠 CF 㦥 ⠭,   㬬 ਡ 1:
             
                              WORD1A         0123
                              WORD2A         0012
                               ७      1
                              㬬:         0136
             
                ᯮ짮   ⫠稪   DEBUG    ஢
          䬥᪨      㢨     㬬  0136  
          ॣ AX,  p 祭 3601   WORD3A  9C11 
           WORD3B.
               .12.2  楤  E10DWD    室  
          ᫮  祭    .   ⢨  稭  
          ᫮  ᠬ ࠢ  ᫮  ᪫뢠  .   ࢮ
          横  ᪫뢠   ࠢ  c,     ஬  -  ᫮,
          ᯮ .  ⮬   ॣ SI, DI  BX
          㬥  2.    DEC 믮   
            ॣ. ਬ 
             
                              SUB  reg,02
             
              砥  ,  ..   ⮬ 㤥 饭 䫠
          ७,  ਢ  ᪠ १ ᫮.
                横,  ᯮ  ⮫쪮   
          ᫮  ADC.  ।  横    CLC  (CLear  Carry -
           䫠 ७) ⠭ 㫥 祭 䫠
          ७.   ࠡ   ⮤  室: 1) ᯥ
           ᬥ ᫮,  2) 믮 ࠡ ࠢ  
          3) 㧨  ॣ CX ᫮ ᪫뢠 ᫮.
               ᫮  ⠭  ᯮ    SBB
          (SuBtract with  Borrow  -  ⠭  ) ⭠
           ADC.    楤  E10DWD (.12.2) 
          ADC  SBB, 稬 楤  ⠭.
          
             
          ------------------------------------------------------------
          


          
          ᥬ  IBM PC.  12                           265


              ᫮        ,  ਬ, 
          , a .  ᫮  ।
          ᥣ ⥫,  ਬ, ଠ 믫,  ,
          祭 ᫠  .  㣨 ᫮   ,
          ⠪        ᮤন       ⥫  
          ⥫. ਬ,   㯠⥫, 
            ⥫   ९,  ࠨ᪮
          ᫮.
               稭    ⠬  
           ࠭祭 +32767  ॣ  ᮤঠ  ᫠ 
          +65535.     稭     
          ⮬.   ADD   SUB   ࠧ  묨
           묨 稭,    ᪫뢠  
          .    ᫥饬 ਬ  ᫮     ᥫ,
          ࢮ ᫮ ᮤন    .  
          ᫠     ।⠢  ⥫쭮   ᫮  249,  
           - ⥫쭮 ᫮ -7:
             
                                       
                    11111001            249            -7
                    00000010              2            +2
                    11111011            251            -5
          
          筮  ।⠢  १  ᫮   
              ᫠.  ,   ।⠢
          +251      ᫠    -5    . 
          ࠧ,  ᫮ ᮤন    ஢
           ࠧ.
             ﭨ "७"   ⮬ 砥,  
          p   ࠧ.  ﭨ "९" 
            ⮬ 砥,   ७   ࠧ  ᮧ
          ७  ࠧ來 ⪨  ७    ࠧ來 ⪨
          நCX  ७   ࠧ.  
          ७  ᫮  ᥫ,  १ 砥
           ࠢ:
             
                                         CF   OF
                    11111100            252            -4
                    00000101              5            +5
                    00000001              1             1    1    0
                                   (ࠢ쭮)
             
                 ९    ᫮  
          ᥫ, १ 砥 ࠢ:
             
                                         CF   OF
                    01111001            121          +121
                    00001011             11           +11
                    10000100            132          -124    0    1
                                               (ࠢ쭮)
             
                ᫮    ⠭   ६
            ९,  ७:

          
          ᥬ  IBM PC.  12                           266


             
                                         CF   OF
                    11110110            246           -10
                    10001001            137          -119
                    01111111            127          +127    1    1
                                   (ࠢ쭮)  (ࠢ쭮)
          
          
          ------------------------------------------------------------
          
               㬭       믮
           MUL,     - IMUL (Integer MULtiplication
          -  㬭  楫 ᥫ).  ⢥⢥  ஫ 
          ଠ⮬ ࠡ뢠 ᥫ   롮  室饩 
          㬭      ᠬ  ணࠬ.     
          ᭮ 樨 㬭:
             
             "  ".  室  ॣ AL,  
          ⥫           ⮢  ॣ. ᫥
          㬭  ந  室   ॣ  AX. 
             p    ,    室 
          ॣ AH.
             
                             AH      AL                 AX       
              㬭:             ᫥:ந
             
             "  ᫮".  室  ॣ AX,  
          ⥫  -    ᫮     ॣ.  ᫥ 㬭
          ந  室       ᫮,     ண
          ॡ  ॣ:    ()  ந
          室  ॣ DX,   (ࠢ)   ॣ
          AX.       ࠥ    , 
          室  ॣ DX.
             
                             AX                DX      AX   
              㬭: ᫥:   .쳳.
                                                 ந   
             
              ⢥  ࠭    MUL   IMUL 㪠뢠
          ⥫. ᬮਬ ᫥ :
             
                                   MUL  MULTR
             
             ᫨    MULTR ।     (DB),  
          । 㬭 ᮤন AL    祭  
           MULTR.  ᫨  MULTR ।   ᫮  (DW), 
           ।  㬭 ᮤন AX   祭
          ᫮   MULTR. ᫨ ⥫ 室  ॣ, 
            ॣ  । ⨯ 樨,    
          :
             
               MUL  CL  ;-⥫:   AL, ந.  AX
               MUL  BX  ;-⥫:  AX, ந. DX:AX

          
          ᥬ  IBM PC.  12                           267


             
              㬭:  MUL
             
              MUL (MULtiplication -  㬭) 㬭 
           ᫠.    .  12.3    楤  C10MUL   
          ਬ 㬭:    ,  ᫮  ᫮  ᫮ 
          .   ਬ   MUL 㬭  .80 (128) 
          .47  (64).  ந - .2000 (8192) 砥 
          ॣ AX.
          
          ------------------------------------------------------------
          ------------------------------------------------------------
                    . 12.3.    㬭.
          
             ன  ਬ   MUL   .  10000000 
          ॣp DX:AX.
             ⨩  ਬ   MUL 믮 㬭  ᫮ 
            ॡ ७  BYTE1  ࠧ஢ ᫮. 
           ।  稭,    ਬ 
           ॣ AH ࠢ .  ( ᯮ짮   CBW
          祭     ॣp  AL      0   1).
          ந - . 00400000 砥  ॣ DX:AX.
             
              㬭:  IMUL
             
               IMUL  (Integer MULtiplication -  㬭 楫
          ᥫ)  㬭   ᫠.   .  12.3  楤
          D10IMUL ᯮ     ਬ 㬭,     
          楤  C10MUL,       MUL  ᠭ 
          IMUL.
              ਬ   IMUL  㬭 .80 (⥫
           ᫮)    .40  (⥫쭮 ᫮). ந
          -  .E000  砥    ॣ  AX.  ᯮ   
          ,   MUL    १  .2000,  ⠪ 
              ࠧ  ᯮ짮    MUL   IMUL.
           MUL ᬠਢ .80   +128,    IMUL
          -   -128.   १ 㬭 -128   +64 砥
          -8192   .E000.  (஡ ८ࠧ .000 
           ଠ).
             ன ਬ  IMUL 㬭 .8000 (⥫
             祭)     .2000   (⥫쭮  祭).
          ந -  .F0000000 砥  ॣ DX:AX 
          ।⠢ ᮡ o⥫쭮 祭.
             ⨩  ਬ   IMUL   । 㬭 믮
          ७  BYTE1   ࠧ஢ ᫮  ॣ AX. 
             祭  ।   ,        ਬ
          ᯮ  CBW  ॢ    
           ॣ AH: .80  p AL ॢ頥  .FF80
            ॣ  AX.  ᪮  ⥫   ᫮  WORD1 
          ⠪   ⥫쭮   祭,     ந  
            ⥫쭮.    ᠬ  :  .00400000  



          
          ᥬ  IBM PC.  12                           268


          ॣ  DX:AX  -  ⠪    १,       砥
          㬭   MUL,   । ⥫
          ᮬ⥫.
              ࠧ, ᫨   ⥫  
           ,    MUL    IMUL  
          १.  , ᫨ ᮬ⥫  ࠧ  ,
                MUL   ࠡ뢠   ⥫  १
          㬭,   IMUL - ⥫.
               㦨  ,   ᯮ  ⫠稪  DEBUG  
          ஢ ਬ஢.
             
             襭  䥪⨢  㬭:     㬭  
          ⥯ ᫠ 2  (2,4,8   ..)   䥪⨢ 
          ᤢ   ॡ㥬 ᫮ ⮢.    祬   1
          ॡ 㧪 稭  ᤢ  ॣ  CL.  ᫥
          ਬ ।,    室   ॣ AL
           AX:
             
                           2:     SHL  AL,1
                           8:     MOV  CL,3
                                             SHL  AX,CL
             
             ᫮ 㬭
             
             筮 㬭   ⨯: "  "   "᫮
            ᫮".    㦥 뫮  ,  ᨬ쭮 
          祭    ᫮  ࠭祭  稭  +32767. 
           ᥫ  ॡ  믮   ⥫
          ⢨.   ᬠਢ  室  ।  㬭
           ᫮ ⤥쭮    ᫮  祭 १⮢.
          ᬮਬ ᫥饥 㬭  筮 ଠ:
             
                                   1365
                                    12
                                   2730
                                   1365
                                  16380
          
          ।⠢,   筠 䬥⨪  㬭 ⮫쪮
          姭  ᫠.     㬭  13    65   12
          ࠧ쭮, c騬 ࠧ:
          
                          13             65
                         12            12
                          26            130
                          13             65
                         156            780
          
          騬 蠣 ᫮ 祭 ந,  ᪮
          ᫮  13  ।⠢﫮  ⭨,    ࢮ  ந  
          ⢨⥫쭮 㤥 15600:
          
                              15600

          
          ᥬ  IBM PC.  12                           269


                               +780
                              16380
             
             ᥬୠ ணࠬ ᯮ   孨 
          ᪫祭 ⮣,     ࠧ୮ ᫮ (
          )  ⭠筮 ଠ.
             
               ᫮   ᫮.  楤 E10XMUL 
          .12.4 㬭  ᫮  ᫮. , MULTCND,
          ⮨   ᫮, ᮤঠ ᮮ⢥⢥ . 3206 
          . 2521. ।      ᫮ (DW) 
           ᫮  (DD)  ᫮  室 ࠢ쭮
          樨    MOV,  뫠 ᫮  ॣ AX.
          ⥫  MULTPLR ᮤন  .  6400.   
          ந,  PRODUCT, ⮨   ᫮. ࢠ 
          MUL  ६  MULTPLR    ࠢ  c     MULTCND;
          ந  -  .  0E80 E400 뢠  PRODUCT+2 
          PRODUCT+4.    MUL ६  MULTPLR   
          ᫮   MULTCND,    १  . 138A 5800.
            믮  ᫮     ந  ᫥騬
          ࠧ:
             
                    ந1: 0000 0E80 E400
                    ந 2:     138A 5800     
                    :          138A 6680 E400
          
            ࢠ    ADD    ࠡ  ७, 
          ஥ c 믮    ᫮   ७ᮬ
          ADC (ADd with Carry).  ᨫ  ⭮ ।⠢ ⮢
           ᫮  p 8086/8088,   PRODUCT  ⢨
          ⥫쭮   㤥   ᮤঠ   祭   8A13  8066  00E4.
          ணࠬ   ।,     ࢮ   ᫮     
          PRODUCT  砫쭮 祭 0000.
          
          ------------------------------------------------------------
          ------------------------------------------------------------
                    .12.4. ᫮ 㬭.
             
               " ᫮     ᫮". 
               ᫮  砥  ᫥騥     樨
          㬭:
          
                                ⥫
          
                         ᫮ 2       ᫮ 2
                         ᫮ 2       ᫮ 1
                         ᫮ 1       ᫮ 2
                         ᫮ 1       ᫮ 1
          
            ந   ॣ  DX    AX  ᪫뢠 
          ᮮ⢥騬  ᫮   ⥫쭮  १. ਬ
          ⠪ 㬭 ਢ  楤 F10XMUL   . 12.4.


          
          ᥬ  IBM PC.  12                           270


           MULTCND ᮤন . 3206 2521, ⥫ MULTPLR
          -  .  6400  0A26.     PRODUCT,
             ᫮.
                㬭  ᫮  筠 㬭
           ᫮   ᫮,      ᮡ, ᫥
            ᫮  ADD/ADC ᯮ    
          ADC,   ਡ  0   祭    PRODUCT. 
          室 ⮬,  ࢠ  ADC ᠬ  맢
          ७,   ᫥騥   . ⮬
              ADC  ਡ  0,   ᫨  ७  ,  
          ਡ 1, ᫨ ७ . 쭠   ADD/ADC
            ।  ⥫쭮    ADC,  ⠪   
          PRODUCT  筮       樨  ⥫쭮
          १  ७  ᫥ ⠯  㤥.
             ⥫ १  138A 687C 8E5C  CCE6  
            PRODUCT    ⭮      ᫮. 믮
          ஢ ⮣ ਬ   ⫠稪 DEBUG.
          
             DX:AX
          ------------------------------------------------------------
             
               ணࠬ         ᤢ
          ᮤন p஢   DX:AX ࠢ   . 
          ਤ㬠      䥪⨢  ⮤,       ਬ
          ।⠢  騩  室      ᫠  横  (,
          ᮮ⢥⢥,  ᤢ)  ॣ CX. ,  ᤢ
          筮      ࠧ來     ⠭  䫠
          ७.
             
                                  4 
                         MOV  CX,04     ;樠  4 横
                    C20: SHL  DX,1      ; DX  1  
                         SHL  AX,1      ; AX  1  
                         ADC  DX,00     ;ਡ 祭 ७
                         LOOP C20       ;
                                ࠢ  4 
                         MOV  CX,04     ;樠  4 横
                    D20: SHR  AX,1      ; AX  1  ࠢ
                         SHR  DX,1      ; DX  1  ࠢ
                         JNC  D30       ;᫨  ७,
                         OR   AH,10000000B   ;   ⠢ 1  AH
                    D30: LOOP D20       ;
             
              ਢ  䥪⨢ ᯮᮡ   ᤢ ,
           ॡ騩 ࣠樨 横.  ⮬ ਬ 䠪 ᤢ
          뢠   ॣ CL.  ਬ ᠭ  ᤢ   4
          ,    ஢  㣨 稭 ᤢ:
             
                         MOV  CL,04     ;⠭ 䠪 ᤢ
                         SHL  DX,CL     ; DX   4 
                         MOV  BL,AH     ;࠭ AH  BL
                         SHL  AX,CL     ; AX   4 
                         SHL  BL,CL     ; BL ࠢ  4 

          
          ᥬ  IBM PC.  12                           271


                         OR   DL,BL     ; 4   BL  DL
             
          
          ------------------------------------------------------------
             
                        믮
            DIV,  a    -  IDIV.  ⢥⢥ 
           室饩     ணࠬ. 
           ᭮ 樨 :
             
              "᫮  ".  室  ॣ AX,
           ⥫  -         ⮢ ॣ.
          ᫥  ⮪ 砥  ॣ AH,   ⭮ -
           AL.    ⮢ ⭮ 祭   (ᨬ쭮
          +255 (.FF)     +127 (.7F) 
          ),                ࠭祭
          ᯮ짮.
             
                             AX                   AH     AL   
              :       ᫥:    ⮪⭮
             
               " ᫮   ᫮".   室 
          ॣ஢  DX:AX,   ⥫  -   ᫮   
          ॣ.  ᫥  ⮪ 砥  ॣ DX, 
          ⭮   ॣ  AX.  ⭮      ᫮ ᪠
          ᨬ쭮  祭  +32767  (.FFFF)  
            +16383 (.7FFF)  .
             
                           DX      AX             AH     AL   
              :.쳳.  ᫥:⮪⭮
                                   
             
            ⢥  ࠭    DIV    IDIV  㪠뢠
          ⥫. ᬮਬ ᫥ :
             
                                   DIV  DIVISOR
             
             ᫨  DIVISOR ।     (DB),  
          ।    ᫮    .  ᫨    DIVISOR
          ।  ᫮ (DW),    । 
           ᫮  ᫮.
               ,  ਬ,  13  3, 砥 ࠧ 4
          1/3.  ⭮    4,   ⮪ -  1. ⨬,  筮
           (  ணࠬ   몥 BASIC)  뤠   ⮬
          砥 १ 4,333.... 祭 ᮤন 楫  (4)
           ஡  (,333).  祭 1/3   333...  ஡
          ,   ६  1  ⮪  .
             
              :  DIV
             
               DIV      ᫠.    .12.5  
          楤 D10DIV   ਬ : ᫮  ,
             ,    ᫮   ᫮   ᫮   ᫮.

          
          ᥬ  IBM PC.  12                           272


           ਬ  DIV  .2000  (8092)  .80
          (128).   १ ⮪ 00  砥  ॣ AH, 
          ⭮ .40 (64) -  ॣ AL.
             ன ਬ    DIV  믮  ० ७
           BYTE1   ࠧ஢ ᫮.    ।
           稭,    ਬ      ॣ AH
          ࠢ .  १  ⮪ - . 12 砥
            ॣ AH,  ⭮ .05 -  ॣ AL.
             ⨩ ਬ  DIV  ⮪ . 1000 
          ॣ DX  ⭮ . 0080  ॣ AX.
               ⢥⮬  ਬ    DIV  ᭠砫  믮
          ७ ᫮ WORD1      ᫮    ॣ DX.
          ᫥  ⮪ .0000     ॣ DX, 
          ⭮ . 0002 -  ॣ AX.
          
          ------------------------------------------------------------
          ------------------------------------------------------------
                    .15.5.    .
             
              :  IDIV
             
              IDIV (Integer DIVide)  믮  
          ᥫ.   .12.5   楤 E10IDIV ᯮ   
           ਬ ,     楤 D10DIV,  
              DIV  ᠭ  IDIV.   ਬ 
          IDIV  .2000  (⥫쭮 ᫮)  .80 (
          ⥫쭮 ᫮). ⮪   - . 00 砥 
          ॣ AH ,   ⭮ -  .  C0 (-64) -  ॣ AL.
           DIV, ᯮ   ᫠,  ⭮ +64.
             ⭠  १     ⠫  ਬ஢
           ਢ :
             
             ਬ  IDIV        ⮪        ⭮
             
                         2              EE (-18)       FB (-5)
                         3            1000 (4096)    0080 (128)
                         4            0000           0002
          
          쪮  ਬ 4  ࠡ뢠 ⠪  १,  
            DIV.    ࠧ,  ᫨     ⥫
                ,      DIV    IDIV
            p. , ᫨   ⥫
           ࠧ  ,   DIV  
          ⥫쭮  ⭮,    IDIV  -  ⥫쭮 ⭮.
            㦨  ,  ᯮ ⫠稪 DEBUG  
          ஢  ਬ஢.
          
             襭  ந⥫쭮.        ⥯
          ᫠ 2  (2,  4,   ..)    䥪⨢  ᤢ
          ࠢ    ॡ㥬  ᫮  ⮢.    ᫥  ਬ
          ।,   室  ॣ AX:
             
                      2:       SHR  AX,1

          
          ᥬ  IBM PC.  12                           273


                      8:       MOV  CL,3
                                        SHR  AX,CL
             
             ९  뢠
             
             ᯮ    DIV    ᮡ  IDIV,  祭 
          맢 p.  뢠  ਢ ( ࠩ 
            ⥬,  ᯮ㥬  ஢   ணࠬ) 
          ।᪠㥬 १⠬.     ।
          ,   ⭮ ⥫쭮 ,  祬 . 
              ᥣ  뢠  뢠.         1
           ⭮,  ஥ ࠢ ,   ⠪
           맢 뢠.
                ᯮ짮   ᫥饥   ࠢ:  ᫨
          ⥫  -  ,    祭    , 祬
              (AH)  ⥫:  ᫨ ⥫ -  ᫮,  
          祭   ,  祬  ᫮ (DX) ⥫.
          ந㥬  ࠢ  ⥫, ࠢ 1:
             
              :             ⥫  ⭮
               :                0123        01     (1)23
              ᫮  ᫮:  0001 4026      0001   (1)4026
             
             ⭮ ॢ蠥  ࠧ.  ⮣
          ⮡     権,   ⠢ ।
           DIV   IDIV ᮮ⢥ ஢.   ࢮ 
          ᫥ ਬp  ।,   DIVBYTE - ⮢
          ⥫,    室 㦥  ॣ AX.   ஬
          ਬ ।,   DIVWORD - 塠⮢ ⥫, 
           室  ॣ஢  DX:AX.
          
                                   ᫮  
          
                    CMP  AH,DIVBYTE          CMP  DX,DIVWORD
                    JNB  ९        JNB  ९
                    DIV  DIVBYTE             DIV  DIVWORD
             
               IDIV    뢠  䠪,
            ,  ⥫   ⥫묨, 
          ⠪    ࠢ  ᮫  祭,   室
          ᯮ짮      NEG        ६   ॢ
          ⥫쭮 祭  ⥫쭮.
             
              ⠭
             
             ᫨ ⭮ ᫨誮 ,    믮 
           横᪮ ⠭. ⮤ 砥  ⮬, 
          ⥫ ⠥      ⮬    横 ⭮
          㢥稢   1.  ⠭  த,   
          ⠥    ⥫.    c饬  ਬ, ⥫
          室    ॣ  AX,       -    BX,  ⭮
          ࠡ뢠  CX:
             

          
          ᥬ  IBM PC.  12                           274


                    SUB  CX,CX     ;⪠ ⭮
               C20: CMP  AX,BX     ;᫨  < ⥫,
                    JB   C30       ;   
                    SUB  AX,BX     ;⠭ ⥫  
                    INC  CX        ;६ ⭮
                    JMP  C20       ; 横
               30: RET            ;⭮  CX, ⮪  AX
             
               ணࠬ ॣ CX 㤥  ᮤঠ ⭮,
           AX - o⮪. ਬ 諥 ਬ⨢  樨
           孨  .  ᫨ ⭮ 砥  ॣ
            DX:AX,  室 ᤥ  :
             
             1.  ⪥ C20 ࠢ AX  BX  ⮫쪮  㫥 DX.
             2. ᫥  SUB ⠢  SBB DX,00.
             
             ਬ砭: 祭 讥  ⭮   ⥫ 
          맢  横.
          
           
          ------------------------------------------------------------
          
              NEG  ᯥ稢  ८ࠧ   
          ᥫ    ⥫쭮      ⥫쭮     .
          ࠪ᪨      NEG   ⠭  ⨢
          祭 ⮢  ਡ 1. ਬ:
             
                         NEG  AX
                         NEG  BL
                         NEG  BINAMT    (  ᫮  )
             
             ८ࠧ   35-⮢ ( 襣) ᫠
          砥   蠣.  ।,    ॣ஢ 
          DX:AX ᮤন  32-⮢  筮 ᫮.    
          NEG   ࠡ뢠   ॣ  ६,  
          ᯮ짮 ਢ  ࠢ쭮  १.  ᫥
          饬 ਬ  ᯮ짮  NOT:
             
                         NOT  DX   ;஢ ⮢
                         NOT  AX   ;஢ ⮢
                         ADD  AX,1 ;ਡ 1  AX
                         ADC  DX,0 ;ਡ ७  DX
             
             ⠥    ⥫쭠   ஡:    ᫠,
          ।⠢묨  筮 ଠ,  㤮 믮 䬥
          ᪨ 樨,  ᫨ ᠬ ᫠ ।   ணࠬ.
          ,    ணࠬ  ᪮ 䠩,  ⠪
             ଠ.   ,     ,
          ।⠢  ASCII-ଠ.    ASCII-  㤮 
          ⮡ࠦ  ,  ॡ ᯥ樠 ८ࠧ
            ଠ  䬥᪨ ᫥.    㦥
          ⥬ ᫥饩 .
             

          
          ᥬ  IBM PC.  12                           275


           INTEL 8087  80287    
          ------------------------------------------------------------
             
             ⥬        ᮤন  ⮥  ,
          १ࢨ஢   ᫮   Intel 8087 (
          80287).  8087  ᮢ⭮  8088,  ᮯ
           80287  ᮢ⭮  80286.  ᮯ
           ᮡ⢥      ।⢠    権 
          饩   ⮩        믮   ᯮ樠,
          䬨᪨    ਣ᪨  㭪権. 
          ᮤন  ᥬ  80-⮢ ॣ஢   饩 ⮩,
            ।⠢ ᫮ 祭  10   400 
          .  ⥬᪨ ᫥   ᮯ 믮
          ਬ୮  100 ࠧ ॥, 祬  ᭮ .
             ᭮    믮  ᯥ樠   樨  
          । ᫮     ᮯ,   믮
          室 ᫥  頥 १.   ᥬ
          ஢     ࠭  MASM,  室 
          ࠬ /E  /R, ਬ, MASM /R.
             
             
          ------------------------------------------------------------
          
               ᮡ ⥫  ᯮ짮 
                p஢.    祭     
               -128  +127.
          
               ᫮ ᫮ ᯮ   ADC 
                 ७ᮢ  । ᫮.  ᫨ 
               믮      横,     ᯮ    CLC,
               ⠭ 䫠 ७  0.
          
              ᯮ  MUL  DIV    
                 IMUL  IDIV  .
          
                   ஦    ९ﬨ. ᫨
               㫥 ⥫ ,   ᯥ ஢ ⮩
               樨.  ஬  ⮣,  ⥫      
               ᮤন ॣ AH ( )  DX ( ᫮).
          
               㬭    ⥯  ᯮ
               c.  ࠢ 믮  SHR  
                     SAR      . 
               ᤢ  ᯮ   SHL  SAL.
          
               ⥫    ᥬ஢   㬮砭.
               ਬ,  ᫨   FACTOR ।    (DB),
                 MUL FACTOR     ॣ AL,
                 DIV FACTOR       ॣ AX.
               ᫨ FACTOR  ।  ᫮ (DW),     MUL
               FACTOR    ॣ  AX,    DIV
               FACTOR    ॣ஢  DX:AX.
          

          
          ᥬ  IBM PC.  12                           276


            
          ------------------------------------------------------------
          
                   ⭮襭  ᫥騬 :
          
                              DATAX     DW   0148H
                                        DW   2316H
                              DATAY     DW   0237H
                                        DW   4052H
          
          12.1.     ᫮  )  ᫮  DATAX 
                ᫮  DATAY;  )    ᫮,  稭饣 
                 DATAX,   ᫮  DATAY.
          
          12.2. ᭨ ⢨ ᫥ :
          
                                   STC
                                   MOV BX,DATAX
                                   ADC BX,DATAY
          
          12.3.      㬭  (MUL):  )  ᫮
                DATAX  ᫮ DATAY;  )  ᫮ , 稭饣
                   DATAX,  ᫮ DATAY.
          
          12.4.    ⥫,    ஬   ,   뢠   訡
                ९?
          
          12.5.     (DIV): )  ᫮ DATAX
                  23;  )   ᫮,  稭饣   
                DATAX,  ᫮ DATAY.
          
          12.6. ᫥  ਬ   ࠧ  "  ॣ஢ 
                DX:AX"      䥪⨢    ࠢ  
                ।騬 ਬࠬ  ᤢ    .
                 ਬ  ᤢ ࠢ   .



















          
