[[eduarcol]]

Segun lo poco que entendi tengo unas propuestas, son dos lineas basicamente las puse en rojo para que las identifiques. En la primera devuelvo cero si el resultado es correcto, y en la segunda lo agrego al memo

Código Delphi [-]
unit Unit1;
interface
uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls,Forms,
 Dialogs, StdCtrls;
 type
 TForm1 = class(TForm)
 Memo1: TMemo;
 Button1: TButton;
 Button2: TButton;
 Label1: TLabel;
 OpenDialog1: TOpenDialog;
 procedure Button1Click(Sender: TObject);
 procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  Form1: TForm1;
implementation
{$R *.dfm}
  type buffer=array of byte;  //assign as Dynamic array
  var HexBuf:buffer;
 function ByteToHex(InByte:byte):shortstring;
const Digits:array[0..15] of char='0123456789ABCDEF';
begin
 result:=digits[InByte shr 4]+digits[InByte and $0F];
end;
  function readline(HexLine:string; var Buf:buffer):integer;
  var ADDR,count:integer;
  CHKSUM,SUMLINE,RECLEN,RECTYPE,DATA:byte; t:shortstring;
  begin
  // Array length may be change, here is 100,000
 SetLength(HexBuf,100000);
 if HexLine[1]=':' then begin
 t:='$'+copy(HexLine,2,2);   // get length
 RECLEN:=strtoint(t);
 CHKSUM:=0;
 CHKSUM:=CHKSUM+RECLEN;
 t:='$'+copy(HexLine,4,4); // get address
 ADDR:=strtoint(t);
 CHKSUM:=CHKSUM+lo(ADDR)+hi(ADDR);
 t:='$'+copy(HexLine,8,2);
 RECTYPE:=strtoint(t);
 CHKSUM:=CHKSUM+RECTYPE;
 case RECTYPE of
 0:begin             // datablock
 count:=0;
 while (count < RECLEN) do begin
 t:='$'+copy(HexLine,10+2*count,2);
 DATA:=strtoint(t);
 CHKSUM:=CHKSUM+DATA;
 Buf[ADDR+count]:=DATA;
 inc(count);
 end;
 t:='$'+copy(HexLine,10+2*count,2);
 SUMLINE:=strtoint(t);
 Result := 0;
 end;
 1:begin   // end of file
 t:='$'+copy(HexLine,10,2);
 SUMLINE:=strtoint(t);
 result:=1;
 end;
 else
 begin
 result := -2;  // invalid record type
 exit;
 end;
 end; //case
 // test checksum
 DATA:=SUMLINE+CHKSUM;
 if (DATA<>0) then result:=-3; // checksum error
 end
 else result:=-1; // no record
 end;
procedure TForm1.Button1Click(Sender: TObject);
var Fname,line:string;
Fp : textfile;
 ErrorCode:integer;
begin
 Fname:='test.hex';
 AssignFile(Fp,Fname); { File selected in dialog }
 Reset(Fp);
 while not eof(Fp) do
   begin
  Readln(Fp,line);{ Read first line of file }
  ErrorCode := readline(line,HexBuf);
   if (ErrorCode=0) then
  begin
   // Do some thing if read one line OK
   // such send data to serial port,parallel port etc.
      Memo1.Lines.Add(ByteToHex(HexBuf));
   end
    else
  begin
  // Error handle here
  //  0 = No error
  // -1 = File not Intel Hex format
  // -2 = Invalid record type
  // -3 = Checksum error
   end;
    end;
   CloseFile(Fp);
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
if OpenDialog1.Execute then
begin
Label1.Caption:=OpenDialog1.FileName;
end;
end;
end.