{****************************************************************************
 *                       Pascal SAMPLE: SAMPLE5.PAS                         *
 *                                                                          *
 *  This is a demonstration program to be used with the ad8 A/D            *
 *  board.  The program will constantly read the digital input until a      *
 *  key is pressed.  When a key is pressed the program exits.               *
 *                                                                          *
 *  This program demonstrates the use of task 0 to initialize the driver    *
 *  and task 2 to read digital I/O.                                         *
 *                                                                          *
 *  Set the IRQ jumper to IRQ5.                                             *
 *                                                                          *
 *  LAST MODIFICATION: 2/4/98                                               *
 *                                                                          *
 ****************************************************************************}
program sample5;
{$L ad8drv}
{$F+}

USES crt;

type param_array = array[1..5] of integer;

{ all of the parameters passed to the AD12DRV driver must be declared
 globally, including the buffers which have their offset passed inside
 the params array }

var  task,status                        : integer;
     param                              : param_array;


procedure ad8drv(t_off:word;p_off:word;st_off:word);external;


function AskForBaseAddress(OldOne : String) : Word;
const
   Msg : string[4] = '0';
var
   NewOne, Success, Dummy, Error : Word;
   AddrInputPosX, AddrInputPosY : Word;
begin
   if (OldOne = 'OLD') then OldOne := Msg;
   WriteLn('Please enter the Base Address (0000-FFFF) for your card (in hex)');
   WriteLn('or press ENTER for ', OldOne, '.  ');
   Write('>');
   AddrInputPosX := WhereX; AddrInputPosY := WhereY;
   repeat
      GotoXY(AddrInputPosX, AddrInputPosY);
      ClrEol;
      Readln(Msg);
      Val('$' + Msg, NewOne, Error);
      if (error=0) then begin
         Success := 1;
         Dummy := NewOne;
      end else if (Msg = '') then begin
         GotoXY(AddrInputPosX, AddrInputPosY);
         WriteLn(OldOne);
         Msg := OldOne;
         Success := 1;
         Val('$' + Msg, Dummy, Error);
      end;
   until (Success = 1);
   AskForBaseAddress := Dummy;
end;  { end of AskForBaseAddress }



{***************************************************************************
 * PROCEDURE: call_driver -- local routine                                 *
 *                                                                         *
 *   PURPOSE: Performs the call to the driver package.                     *
 *                                                                         *
 *     INPUT: None.                                                        *
 *                                                                         *
 *     CALLS: ad8drv - entry point to driver package.                     *
 *                                                                         *
 *    OUTPUT: None.                                                        *
 *                                                                         *
 ***************************************************************************}
procedure call_driver;

begin
     ad8drv(ofs(task),ofs(param[1]),ofs(status));

   { this section checks for an error code  }

   if status > 0 then
      begin
      WriteLn('A status error code of ',status,' was detected.');
      WriteLn('Program terminated.');
      end;
end; { call_driver }

{****************************************************************************
 *  FUNCTION: main -- local routine                                         *
 *                                                                          *
 *   PURPOSE: Inputs data from the digital input bits.                      *
 *                                                                          *
 *     INPUT: None.                                                         *
 *                                                                          *
 *     CALLS: call_driver                                                   *
 *                                                                          *
 *    OUTPUT: None.                                                         *
 *                                                                          *
 ****************************************************************************}
var
  ch      : string;
  Address : word;
BEGIN
   ClrScr;

   WriteLn('                 SAMPLE5.PAS : AD8-16 DIGITAL DATA');
   WriteLn;
   WriteLn('This is a demonstration program to be used with the AD8 A/D board.');
   WriteLn('The program will constantly read the digital input until a key is pressed.');
   WriteLn('When a key is pressed the program exits.');
   WriteLn;
   Address := AskForBaseAddress('350');
   ClrScr;
   WriteLn;
   WriteLn;
   WriteLn;
   WriteLn('Board Configuration:');
   WriteLn;
   WriteLn(' -- Jumper IRQ5 should be installed        (required)');
   WriteLn(' -- Differential mode inputs               (required)');
   WriteLn(' -- All remaining jumper settings are irrelevant.');
   WriteLn;
   WriteLn;
   WriteLn('Please press any key to run the program.');
   while not keypressed do;
   ch := ReadKey;
   ClrScr;

   task := 0;              { Setup driver                             }
   param[1] := Address;    { Assign the Base Address                  }
   param[2] := 0;          { differential mode inputs, 1 would be S/E }
   param[3] := 1;          { bipolar mode, 0 would be unipolar        }
   param[4] := 5;          { IRQ line jumpered on board               }
   call_driver;
   if status > 0 then halt;

   GotoXY(1,7);
   WriteLn('Digital value read:');
   WriteLn;
   WriteLn;
   WriteLn;
   WriteLn('Press any key to terminate the program.');
   task := 2;                  { Read digital input task          }
   while keypressed = FALSE do { loop until key is pressed        }
      begin
      call_driver;             { call the driver to read digital  }
      if status > 0 then       { if error then exit               }
         begin
         ClrScr;
         halt;
         end;
      GotoXY(21,7);
      WriteLn(param[1]);       { print the digital value          }
      end;
   ClrScr;
END.