v4.0/src/CMD/GRAPHICS/GRINT2FH.ASM

   1         PAGE    ,132                                                            ;AN000;
   2         TITLE   DOS - GRAPHICS Command  -       Interrupt 2FH Driver            ;AN000;
   3                                                                                 ;AN000;
   4 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;                                   ;AN000;
   5 ;; DOS - GRAPHICS Command
   6 ;; (C) Copyright 1988 Microsoft
   7 ;;                                                                              ;AN000;
   8 ;; File Name:  GRINT2FH.ASM                                                     ;AN000;
   9 ;; ----------                                                                   ;AN000;
  10 ;;                                                                              ;AN000;
  11 ;; Description:                                                                 ;AN000;
  12 ;; ------------                                                                 ;AN000;
  13 ;;       This file contains the Interrupt 2FH driver.                           ;AN000;
  14 ;;                                                                              ;AN000;
  15 ;; Documentation Reference:                                                     ;AN000;
  16 ;; ------------------------                                                     ;AN000;
  17 ;;       OASIS High Level Design                                                ;AN000;
  18 ;;       OASIS GRAPHICS I1 Overview                                             ;AN000;
  19 ;;                                                                              ;AN000;
  20 ;; Procedures Contained in This File:                                           ;AN000;
  21 ;; ----------------------------------                                           ;AN000;
  22 ;;       INT_2FH_DRIVER - Interrupt 2FH driver                                  ;AN000;
  23 ;;                                                                              ;AN000;
  24 ;; Include Files Required:                                                      ;AN000;
  25 ;; -----------------------                                                      ;AN000;
  26 ;;       GRLOAD.EXT - Externals for profile load                                ;AN000;
  27 ;;       GRCTRL.EXT - Externals for print screen control                        ;AN000;
  28 ;;       GRPRINT.EXT - Externals for print modules                              ;AN000;
  29 ;;       GRCPSD.EXT - Externals for COPY_SHARED_DATA module                     ;AN000;
  30 ;;                                                                              ;AN000;
  31 ;; External Procedure References:                                               ;AN000;
  32 ;; ------------------------------                                               ;AN000;
  33 ;;       Calls next Int 2FH handler in the chain.                               ;AN000;
  34 ;;                                                                              ;AN000;
  35 ;; Linkage Instructions:                                                        ;AN000;
  36 ;; --------------------                                                         ;AN000;
  37 ;;       Refer to GRAPHICS.ASM                                                  ;AN000;
  38 ;;                                                                              ;AN000;
  39 ;; Change History:                                                              ;AN000;
  40 ;; ---------------                                                              ;AN000;
  41 ;;                                                                              ;AN000;
  42 ;;                                                                              ;AN000;
  43 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;                                       ;AN000;
  44                                        ;;                                       ;AN000;
  45                                        ;;                                       ;AN000;
  46 CODE    SEGMENT PUBLIC 'CODE'          ;;                                       ;AN000;
  47         ASSUME  CS:CODE,DS:CODE        ;;                                       ;AN000;
  48                                        ;;                                       ;AN000;
  49         PUBLIC  OLD_INT_2FH            ;;                                       ;AN000;
  50         PUBLIC  INT_2FH_DRIVER         ;;                                       ;AN000;
  51         PUBLIC  PRT_SCR_2FH_NUMBER     ;;                                       ;AN000;
  52         PUBLIC  RESIDENT_CODE_SEG      ;;                                       ;AN000;
  53         PUBLIC  SHARED_DATA_AREA_PTR   ;;                                       ;AN000;
  54                                        ;;                                       ;AN000;
  55                                        ;;                                       ;AN000;
  56 .XLIST                                                                          ;AN000;
  57 INCLUDE STRUC.INC                                                               ;AN000;
  58 INCLUDE GRINST.EXT                                                              ;AN000;
  59 INCLUDE GRCTRL.EXT                                                              ;AN000;
  60 INCLUDE GRCPSD.EXT                                                              ;AN000;
  61 .LIST                                                                           ;AN000;
  62 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;                                       ;AN000;
  63 ;;                                                                              ;AN000;
  64 ;; Module: INT_2FH_DRIVER                                                       ;AN000;
  65 ;;                                                                              ;AN000;
  66 ;; Description:                                                                 ;AN000;
  67 ;;     Respond to GRAPHICS Int 2FH calls.                                       ;AN000;
  68 ;;     The following calls are handled:                                         ;AN000;
  69 ;;                                                                              ;AN000;
  70 ;;      AL = 0 ù Install Check                                                 ;AN000;
  71 ;;                                                                              ;AN000;
  72 ;; Invoked By:                                                                  ;AN000;
  73 ;;     INT 2FH instruction.                                                     ;AN000;
  74 ;;                                                                              ;AN000;
  75 ;; Modules Called:                                                              ;AN000;
  76 ;;     Lower level INT 2FH handlers.                                            ;AN000;
  77 ;;                                                                              ;AN000;
  78 ;; Input Registers:                                                             ;AN000;
  79 ;;     Install Check - AH=15H  AL=0                                             ;AN000;
  80 ;;                                                                              ;AN000;
  81 ;;                                                                              ;AN000;
  82 ;; Output Registers:                                                            ;AN000;
  83 ;;     Install Check:  IF GRAPHICS installed                                    ;AN000;
  84 ;;                        AH=FFH  AL=FFH                                        ;AN000;
  85 ;;                        ES : DI points to Shared Data Area                    ;AN000;
  86 ;;                     ELSE                                                     ;AN000;
  87 ;;                        AH=15H  AL=0                                          ;AN000;
  88 ;;                                                                              ;AN000;
  89 ;; Logic:                                                                       ;AN000;
  90 ;;     IF AH=15H THEN                                                           ;AN000;
  91 ;;        IF AL=0 THEN                                                          ;AN000;
  92 ;;           AH,AL := -1                                                        ;AN000;
  93 ;;           ES : DI := SHARED_DATA_AREA_PTR                                    ;AN000;
  94 ;;        ENDIF                                                                 ;AN000;
  95 ;;        IRET                                                                  ;AN000;
  96 ;;     ELSE                                                                     ;AN000;
  97 ;;        IF OLD_INT_2FH is a valid pointer THEN                                ;AN000;
  98 ;;            Jump to Old Int 2FH                                               ;AN000;
  99 ;;        ELSE                                                                  ;AN000;
 100 ;;            IRET                                                              ;AN000;
 101 ;;        ENDIF                                                                 ;AN000;
 102 ;;     ENDIF                                                                    ;AN000;
 103 ;;                                                                              ;AN000;
 104 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;                                       ;AN000;
 105                                                                                 ;AN000;
 106 INT_2FH_DRIVER  PROC  NEAR                                                      ;AN000;
 107         JMP     INT_2FH                                                         ;AN000;
 108 PRT_SCR_2FH_NUMBER EQU          15H     ; 2FH Multiplex interrupt number        ;AN000;
 109                                         ;  assigned to Print Screen.            ;AN000;
 110 OLD_INT_2FH     DD    ?                 ; Pointer to next 2FH interrupt handler ;AN000;
 111 RESIDENT_CODE_SEG       DW   ?  ; Segment for installed stuff                   ;AN000;
 112 SHARED_DATA_AREA_PTR    DW   ?  ; Offset of the start of the                    ;AN000;
 113                                 ;  Shared Data Area                             ;AN000;
 114                                                                                 ;AN000;
 115 INT_2FH:                                                                        ;AN000;
 116 ;-------------------------------------------------------------------------------;AN000;
 117 ; Verify if the 2FH Interrupt call is for our interrupt handler:                ;AN000;
 118 ;-------------------------------------------------------------------------------;AN000;
 119        .IF <AH EQ PRT_SCR_2FH_NUMBER> AND;If 2FH call is for us                 ;AN000;
 120        .IF <ZERO AL>                    ;  and request is "Get install state"   ;AN000;
 121        .THEN                            ; then,                                 ;AN000;
 122 ;-------------------------------------------------------------------------------;AN000;
 123 ; Yes: return results                                                           ;AN000;
 124 ;-------------------------------------------------------------------------------;AN000;
 125         MOV     DI,CS:SHARED_DATA_AREA_PTR ;  ES:DI :=  Pointer to shared       ;AN000;
 126         PUSH    CS:RESIDENT_CODE_SEG       ;             data area              ;AN000;
 127         POP     ES                      ;                                       ;AN000;
 128         MOV     AH,0FFH                 ; AL and AH := "We are installed"       ;AN000;
 129         MOV     AL,AH                   ;                                       ;AN000;
 130         IRET                            ; Return to interrupted process         ;AN000;
 131 ;-------------------------------------------------------------------------------;AN000;
 132 ; No, pass control to next 2FH interrupt handler:                               ;AN000;
 133 ;-------------------------------------------------------------------------------;AN000;
 134        .ELSE                            ; else, this call is not for us:        ;AN000;
 135          .IF <<WORD PTR CS:OLD_INT_2FH> NE 0> AND ;if there is another          ;AN000;
 136          .IF <<WORD PTR CS:OLD_INT_2FH+2> NE 0> ;  2FH driver                   ;AN000;
 137          .THEN                          ;       below us then,                  ;AN000;
 138             JMP CS:OLD_INT_2FH          ;         pass control to it            ;AN000;
 139          .ELSE                          ;       else, there is nobody to pass   ;AN000;
 140             IRET                        ;         control to, just return.      ;AN000;
 141          .ENDIF                         ;     END If there is a driver below us.;AN000;
 142       .ENDIF                            ;  END If this call is for us.          ;AN000;
 143 INT_2FH_DRIVER  ENDP                                                            ;AN000;
 144                                                                                 ;AN000;
 145 CODE   ENDS                                                                     ;AN000;
 146        END                                                                      ;AN000;