Архив, Вывод архива Опции

[BooM]

Ребят подскажите пожалуйста что с кодом?
писал программу архиватор, проблемма с выводом самого архива кто шарит подскажите пожалуйтса

const
alpha: String = 'abcdefghijklmnopqrstuvwxyz0123456789-.:,;!? '#10#13;

type
TArchiveFile = file of Byte;

var
name , name2 , name3: string;
f : text;

procedure Archive(name, name2: string);
var
text_file: Text;
arch_file: TArchiveFile;

byte_a, byte_b: Byte;

archive_byte, left, right: Byte;

ch: Char;

begin
assign(text_file, name);
reset(text_file);

assign(arch_file, name2);
rewrite(arch_file);

if not eof(text_file) then begin

left := 2;
right := 4;

repeat

if (left = 2) and not eof(text_file) then begin
read(text_file, ch);
byte_a := Pos(ch, alpha);
end else byte_a := byte_b;

if not eof(text_file) then begin
read(text_file, ch);
byte_b := Pos(ch, alpha);
end else
byte_b := 0;

archive_byte := byte(byte_a shl left) or byte(byte_b shr right);

write(arch_file, archive_byte);

if left < 6 then
left := left + 2
else
left := 2;

if right > 0 then
right := right - 2
else
right := 4;

until eof( text_file );

if (right <> 4) and (byte_b <> 0) then
write(arch_file, byte(byte_b shl left));

end;

close(text_file);
close(arch_file);
end;

procedure UnArchive(name2, name3: String);
var
unarchive_byte, byte_a, byte_b, curr_unbyte_num, bytes_done: Byte;
txt_file: Text;
arc_file: TArchiveFile;

last_readed_byte, file_size: LongInt;

begin
assign(txt_file, name2);
rewrite(txt_file);

assign(arc_file, name3);
reset(arc_file);

curr_unbyte_num := 0;
last_readed_byte := -1;
bytes_done := 0;

repeat

inc(bytes_done);

if curr_unbyte_num < 4 then
inc(curr_unbyte_num)
else
curr_unbyte_num := 1;

if curr_unbyte_num = 4 then begin

seek(arc_file, last_readed_byte);
read(arc_file, byte_a);

unarchive_byte := byte(byte(byte_a shl 2) shr 2);

end else if curr_unbyte_num = 3 then begin

seek(arc_file, last_readed_byte);
read(arc_file, byte_a);

seek(arc_file, last_readed_byte + 1);
read(arc_file, byte_b);

unarchive_byte := byte(byte(byte_a shl 4) shr 2) + byte(byte_b shr 6);

inc(last_readed_byte);

end else if curr_unbyte_num = 2 then begin

seek(arc_file, last_readed_byte);
read(arc_file, byte_a);

seek(arc_file, last_readed_byte + 1);
read(arc_file, byte_b);

unarchive_byte := byte(byte(byte_a shl 6) shr 2) + byte(byte_b shr 4);

inc(last_readed_byte);

end else begin

inc(last_readed_byte);
seek(arc_file, last_readed_byte);
read(arc_file, byte_a);

unarchive_byte := byte(byte_a shr 2);
end;

if unarchive_byte <> 0 then
write(txt_file, alpha[unarchive_byte]);

until bytes_done = 8 * (filesize(arc_file)) div 6;

close(txt_file);
close(arc_file);
end;

begin
writeln('Введите путь к файлу: ');
readln(name);
writeln('Введите путь, где будет сохранен будущий архив');
readln(name2);
writeln('Введите куда разархивируется файл: ');
readln(name3);
begin
Assign(f,name3)
end;
Archive(name, name2);
UnArchive(name2, name3);
Writeln('Done');
ReadLn;
end.