{****************************************************************************
 *                    Pascal SAMPLE: SAMPLE3.PAS                            *
 *                                                                          *
 *  This is a demonstration program to be used with the ad8 A/D             *
 *  board.  The program will prompt for a D/A channel and a digital value   *
 *  to output.  Entering a channel > 1 exits the program.                   *
 *                                                                          *
 *  This program demonstrates the use of task 0 to initialize the driver    *
 *  and task 3 to perform D/A conversions.                                  *
 *                                                                          *
 *  Set the IRQ jumper to IRQ5.                                             *
 *                                                                          *
 *  LAST MODIFICATION: 2/4/98                                               *
 *                                                                          *
 ****************************************************************************}
program sample3;
{$L ad8drv}
{$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: Performs digital to analog conversions.                       *
 *                                                                          *
 *     INPUT: None.                                                         *
 *                                                                          *
 *     CALLS: call_driver,                                                  *
 *                                                                          *
 *    OUTPUT: None.                                                         *
 *                                                                          *
 ****************************************************************************}
var
  ch      : string;
  v       : integer;
  c       : integer;
  Address : word;

BEGIN
   ClrScr;

   WriteLn('                   SAMPLE3.PAS : AD8-16 D/A OUTPUTS');
   WriteLn;
   WriteLn('This is a demonstration program to be used with the AD8 A/D board.');
   WriteLn('The program will prompt for a D/A channel and a digital value to output.');
   WriteLn;
   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;
   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;

   { Begin the conversion }

   GotoXY(1,7);
   WriteLn('Enter DAC number (0 or 1, any other to exit):');
   GotoXY(1,9);
   WriteLn('      Enter number of digital counts (0-255):');

   task := 3;               { Analog Output Task      }
   while (status = 0) do    { loop until driver error }
      begin
      GotoXY(48,7);
      readln(param[1]);     { fetch D/A number        }

      if param[1] > 1 then
         begin
         ClrScr;
         halt;              { if not 0 or 1 then exit }
         end;
      GotoXY(48,9);
      readln(param[2]);     { fetch digital value     }
      call_driver;          { go set the DAC          }
      end;
END. { main }