(***************************************************************************)
(**                                                                       **)
(**              DDUtils By John Richardson and Dan Vanderboom            **)
(**            Copyright 1990 John Richardson and Dan Vanderboom          **)
(**                                                                       **)
(**                         TopSoft Support Systems                       **)
(**                         2135 Possum Ct.                               **)
(**                         Brookfield, Wi 53045                          **)
(**                         (414)796-8408 Data 12/24                      **)
(**                                                                       **)
(**                                                                       **)
(***************************************************************************)
(**                                                                       **)
(**                                                                       **)
(** v1.00: Initial Release.                                               **)
(** v1.10: Added 9 more new procedures/functions.                         **)
(** v2.00: Rewrote into assembly                                          **)
(**                                                                       **)
(***************************************************************************)

Unit DDutils;

Interface

Uses Dos;

Function  DDActive:Boolean;
Procedure Give_Time(Amount:Integer);
Procedure Task_Off;
Procedure Task_On;
Function  Invisible:Boolean;
Procedure Switch;
Procedure Resume_Invisible;
Procedure Kill_Other_Job;
Procedure Suspend_Invisible;
Procedure Clear_KeyBoard_Buffer;
Function  Send_Char(Ch:Char):Boolean;
Function  Program_Status:Integer;
Function  Task_Number:Integer;
Function  Other_Status:Integer;
Procedure Time_Sharing(Num:Integer);
Function  Current_TimeShare:Integer;

{=========================================================================}

Implementation

{=========================================================================}

Function DDActive:Boolean; Assembler;
ASM
   MOV AX,0E400H
   INT 21H
   CMP AL,00H
   JE  @not_active
   MOV AL,01H
@not_active:
End;

{=========================================================================}

Procedure Give_Time(Amount:Integer); Assembler;
ASM
   MOV AH,0EEH
   MOV AL,BYTE PTR Amount
   INT 21H
End;

{=========================================================================}

Procedure Task_Off; Assembler;
ASM
   MOV AH,0EAH
   INT 21H
End;

{=========================================================================}

Procedure Task_On; Assembler;
ASM
   MOV AH,0EBH
   INT 21H
End;

{=========================================================================}

Function Invisible:Boolean; Assembler;
ASM
   MOV AX,0E400H
   INT 21H
   MOV BL,AL
   XOR AL,AL  { zero register }
   CMP BL,02H
   JNE @no_invis
   MOV AL,01H
   JMP @done
@no_invis:
   MOV AL,00H
@done:
End;

{=========================================================================}

Procedure Switch; Assembler;
ASM
   MOV AH,0E0H
   MOV AL,1
   INT 21H
End;

{=========================================================================}

Procedure Resume_Invisible; Assembler;
ASM
   MOV AH,0E0H
   MOV AL,73H
   INT 21H
End;

{=========================================================================}

Procedure Kill_Other_Job; Assembler;
ASM
   MOV AH,0E0H
   MOV AL,074H
   INT 21H
End;

{=========================================================================}

Procedure Suspend_Invisible; Assembler;
ASM
   MOV AH,0E0H
   MOV AL,075H
   INT 21H
End;

{=========================================================================}

Procedure Clear_Keyboard_Buffer; Assembler;
ASM
   MOV AH,0E1H
   INT 21H
End;

{=========================================================================}

Function Send_Char(Ch:Char):Boolean; Assembler;
ASM
   MOV AH,0E2H
   MOV DL,BYTE PTR CH
   INT 21H
   CMP AL,0
   JNE @1
   MOV AL,01H
@1:
End;

{=========================================================================}

Function Program_Status:Integer; Assembler;
ASM
   MOV AH,0E4H
   INT 21H
   {Program_Status := Regs.al;}
   { al = 1 program is visible }
   { al = 1 program is invisibile }
   { al = any other value means DoubleDOS not running }
   { ah = task number (0=top, 1=bottom job) }
End;

{=========================================================================}

Function Task_Number:Integer; Assembler;
ASM
   MOV AH,0E4H
   INT 21H
   {MOV AX,AH}
   {Task_Number := Regs.ah;}  { 0=top, 1=bottom }
End;

{=========================================================================}

Function Other_Status:Integer; Assembler;
ASM
   MOV AH,0E5H
   INT 21H
   {MOV AX,AL}
   {Other_Status := Regs.al;}
   { al = 0 no program running   }
   { al = 1 program is running   }
   { al = 2 program is suspended }
End;

{=========================================================================}

Procedure Time_Sharing(Num:Integer); Assembler;
ASM
   { Num Variable }
   { 0 = visible program gets 70% invisible gets 30% (default) }
   { 1 = visible program gets 50% invisible gets 50% of time }
   { 2 = visible program gets 30% invisible gets 70% of time }
   { 3 = top program gets 70% bottom program gets 30% of time }
   { 4 = top program gets 30% bottom program gets 70% of time }
   { 5 = returns current priotity setting in al }
   MOV AH,0E9H
   MOV AL,BYTE PTR Num
   INT 21H
End;

{=========================================================================}

Function Current_TimeShare:Integer; Assembler;
ASM
   MOV AH,0E9H
   MOV AL,5
   INT 21H
   {MOV AX,AL}
   {Current_TimeShare := Regs.al;}
End;

{=========================================================================}

End.