unit Main;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ComCtrls, ExtCtrls, StdCtrls;

type
  TMainForm = class(TForm)
    GroupRange: TRadioGroup;
    GroupOutput: TGroupBox;
    Value: TTrackBar;
    LOutput: TLabel;
    Label2: TLabel;
    GroupChannel: TRadioGroup;
    StatusBar1: TStatusBar;
    Memo1: TMemo;
    ExitButton: TButton;
    Initialize: TButton;
    ISAPanel: TGroupBox;
    Label1: TLabel;
    ISAEdit: TEdit;
    procedure UpdateDAC;
    function ConvertForOutput(V:longword):longword;
    procedure ValueChange(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure ExitButtonClick(Sender: TObject);
    procedure InitializeClick(Sender: TObject);
    procedure FormActivate(Sender: TObject);
    procedure GroupRangeClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  MainForm: TMainForm;

implementation

{$R *.DFM}

uses ACCES32;

  //global variables for internal use
const
  span:double=5.0;
  Offset:double=2.5;
  CurVal:word=0;
  maxch:integer=6;

var
  Address : WORD;
  RunFlag:Boolean;

function TMainForm.ConvertForOutput(v:longword):longword;
  var i:integer;
begin
   if (GroupChannel.ItemIndex < maxch) then //the last item in the channel list is ALL
      outport(Address + (GroupChannel.ItemIndex * 2), v)
   else                           //"all channels" is selected
      for i := 0 to maxch - 1 do
         outport(Address + (i * 2), v);
  result := v;
end;

function IntToBin(input:longword):string;
var
   temp: string;
   i: word;
   f: double;
begin
//this for loop converts to binary
   temp := '';
   for i := 11 downto 0 do begin
      if (input AND (1 shl i)) = 0 then
         temp := temp + '0'
      else
         temp := temp + '1';
   end;  //for;

   temp := temp + 'xxxx';
   f := ((input) * span / 4096 - offset);  //volts

   temp := temp + '  ' + inttohex(input, 3) + ' ' + floattostrf(f, ffFixed, 6, 3);
   if (MainForm.GroupRange.ItemIndex > 4) then
      result := temp + ' mA'
   else
      result := temp + ' Volts';
end;


procedure TMainForm.UpdateDAC;
begin
   LOutput.Caption := IntToBin(ConvertForOutput(CurVal));
end;

procedure TMainForm.ValueChange(Sender: TObject);
begin
   CurVal := value.position;
   UpdateDAC;
end;

procedure TMainForm.FormCreate(Sender: TObject);
var
   i: Integer;
begin
   if (InPortB($61) = $AA55) then begin
      Application.MessageBox('ACCESNT.SYS not detected. Please copy ACCESNT.SYS into [NT]/system32/drivers and re-run this sample.', 'Warning', IDOK);
   end;

   GroupChannel.Items.Clear;//create channel list
   for i:=1 to maxch do
      GroupChannel.Items.Append('Channel '+inttostr(i-1));
   GroupChannel.Items.Append('All Channels');
   GroupChannel.ItemIndex:=0;
   memo1.lines.append('');
   memo1.lines.append('Please configure the dialog options shown to reflect the'+
      ' settings on the card that is installed.  The card''s output voltage shown'+
      ' onscreen will only be correct if these settings are correct.'+
      ' Refer to the card''s manual for specifics about jumper settings and switches.');
   Memo1.ScrollBars:=ssVertical;
end;

procedure TMainForm.ExitButtonClick(Sender: TObject);
begin
   close;
end;

procedure TMainForm.InitializeClick(Sender: TObject);
var
   code,data:integer;
begin
{$R-}
   val('$'+ISAEdit.Text,data,code);
{$R+}
   if ((data > $100) and (data < $3ff)) then begin
      Address := data;
      runflag := True;
   end else
      Beep;
   if runflag then begin
      GroupOutput.visible:=True;
      GroupOutput.enabled:=True;
   end;
end;

procedure TMainForm.FormActivate(Sender: TObject);
begin
   FocusControl(IsaEdit);
end;

procedure TMainForm.GroupRangeClick(Sender: TObject);
begin
   case GroupRange.itemindex of
      0:begin offset:=2.5;span:=5;end;
      1:begin offset:=5;span:=10;end;
      2:begin offset:=10;span:=20;end;
      3:begin offset:=0;span:=5;end;
      4:begin offset:=0;span:=10;end;
      5:begin offset:=-1;span:=4;end;
      6:begin offset:=-4;span:=16;end;
   end;//case
   UpdateDAC;
end;

end.