Why can I use FileSystemObjects for reading and writing client-side binary files, but not for reading and sending them to the server?

Question

I created a binary file in the following manner (to ensure that all the possible byte values are in the binary file):

using (var fs = File.Create(fileName))
{
    for (byte b = 0; b < Byte.MaxValue; b++)
    {
        fs.WriteByte(b);
    }
}

and I read it in this way (for testing that it works):

using (var fs = File.Open(fileName, FileMode.Open))
{
    long oldPos = -1;
    long pos = 0;
    while (oldPos != pos)
    {
        oldPos = pos;
        Console.WriteLine(Convert.ToString(fs.ReadByte(), 2).PadLeft(8, '0'));
        pos = fs.Position;
    } 
}

In javascript in IE, copying the file (reading it, then writing it back out) works just fine when using the FileSystemObject:

var fso = new ActiveXObject("Scripting.FileSystemObject");
var from = fso.OpenTextFile(fileToRead, 1, 0); // read, ASCII (-1 for unicode)
var to = fso.CreateTextFile(fileToWriteTo, true, false); 
while (!from.AtEndOfStream) {
    to.Write(from.Read(1));
}
from.Close();
to.Close();

When I read the outputted binary file, I get 00000000,00000001,00000010... etc.

But attempting to read it into javascript appears to cause the failure to read:

var fso = new ActiveXObject("Scripting.FileSystemObject");
var from = fso.OpenTextFile(fileToRead, 1, 0); 
var test = [];
while (!from.AtEndOfStream) {
    test.push(0xff & from.Read(1));  // make it a byte.
}
from.Close();

which results in test having a bunch of 0's in it's array, and a few other non-zero items, but mostly just 0s.

Can somebody please explain why it works for one and not the other? What do I need to do to get the values into javascript?

By the way, here is a related read on reading files off the client machine:

Answer 1

First, do you know if the length of the final array is the same length as the file ?

Try the read and "Push" in seperate oprations, like:

...  
Test2 = from.Read(1));  
// Possibly display value of Test2 as string  
test.push(Test2);  
...  

Also, you could try this with Text data to see if it is the binary nature of the file/data causing the issue.