Dialer is a small non visual component which allows you to dial phone numbers from your Delphi applications. I am not a great expert in  communications but it works fine for my modem. You can modify it as much as you wish.

Dialer has four published properties, which will appear in you Object Inspector.

ComPort      - Set a communication port of your modem (dpCom1..dpCom4);
Confirm      - true if you wish dialer to ask you if you are sure to dial  the number;
Method       - Dialing method - Pulse or Tone
NumberToDial - string, which contains Phone Number you wish to dial e.g.  '911' :)

You can set these properties from Object Inspector or during the run-time.

There is one public procedure: Execute

After you add an icon representing dialer, you can use TButton component to run it. e.g.

procedure TForm1.Button1Click(Sender: TObject);
begin
  Dialer1.Execute;
end;

You can create the Dialer component "On Fly", without adding its icon to your form:

procedure TForm1.Button1Click(Sender: TObject);
var
  TempDialer : TDialer;
begin
  TempDialer:=TDialer.Create(Self);
  with TempDialer do
  begin
    ComPort:=dpCom4;
    Confirm:=true;
    Method:=dmTone;
    NumberToDial:='1(222)333-4444';
    Execute;
    Free;
  end;
end;

In this case don't forget to add to your uses statement Dialer unit.

To install this control in you VCL place it in your C:\DELPHI\LIB directory and from IDE Options Menu select Install Components. In the Install Components dialog box click Add Button, then in Add Module box type C:\DELPHI\LIB\DIALER.PAS, click OK, then in the Install Components Dialog box click OK again and wait a while. Dialer icon will appear in the Samples section of your Components Palette.

unit Dialer;

interface

uses
  SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
  Forms, Dialogs;

type

  TComPort = (dpCOM1,dpCOM2,dpCOM3,dpCOM4);
  TMethod  = (dmTone,dmPulse);

  TDialer = class(TComponent)
  private
    { Private declarations }
    FComPort : TComPort;
    FNumberToDial : string;
    FConfirm : boolean;
    FMethod : TMethod;
  protected
    { Protected declarations }
  public
    { Public declarations }
    procedure Execute;
  published
    property ComPort : TComPort read FComPort
                 write FComPort;
    property Confirm : boolean read FConfirm
                 write FConfirm;
    property Method  : TMethod read FMethod
                 write FMethod;
    property NumberToDial : string read FNumberToDial
                 write FNumberToDial;
    { Published declarations }
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('Samples', [TDialer]);
end;

procedure TDialer.Execute;
var
  s : string;
  CId : Integer;
  Status : Integer;
  Buf : array[1..32] of Char;
begin
  if FConfirm then
  begin
   if MessageDlg('About to dial the number '+FNumberToDial+'. Are you sure?',
      mtConfirmation, [mbYes,mbNo], 0)=mrNo then Exit;
  end;
  {Create a string to send to modem}
  s:=Concat('ATDT',FNumberToDial,^M^J);
  if FMethod=dmPulse then s[4]:='P';
  {Open Com Port}
  StrPCopy(@Buf,'COM ');
  Buf[4]:=Chr(49+Ord(FComPort));
  CId:=OpenComm(@Buf,512,512);
  if CId<0 then
  begin
    MessageDlg('Unable to open '+StrPas(@Buf),mtError,
                [mbOk], 0);
    Exit;
  end;
  {Send phone number to modem}
  StrPCopy(@Buf,s);
  Status:=WriteComm(CId,@Buf,StrLen(@Buf));
  if Status>=0 then
  begin
    MessageDlg('Pick up the phone',mtInformation,
                [mbOk], 0);
    WriteComm(CId,'ATH'^M^J,5);
  end
  else
    MessageDlg('Unable to dial number',mtError,
                [mbOk], 0);
  {Close communication port}
  CloseComm(CId);
end;

end.