Write Bytes to file, bytes shifted - powershell

Question

I have my bytes stored as string values
like this in file D:\source.txt
208
203
131
132
148
128
128
128
128
128
I just want to read them, and store in another file
I am quite new for powershell, so wrote program like this
$bytes = New-Object System.Collections.ArrayList
foreach($line in [System.IO.File]::ReadLines("D:\source.txt"))
{
[void]$bytes.Add([System.Convert]::ToByte($line));
}
[System.IO.File]::WriteAllBytes("D:\target.zip",[Byte[]]$bytes.ToArray());
So from my undestanding it should get string value, convert it to byte
store it in ArrayList, convert ArrayList to byte array and wrote it to file
And everything goes ok, even if i do echo [Byte[]]$bytes.ToArray() i see correct value
But result file is corrupted, and when i check it byte by byte i see next values
-48
-53
-125
-124
-108
-128
-128
-128
-128
-128
Seems like WriteAllBytes shift my byte values by 128, but why and where?
I am not very professional with powershell, and i cant find anything related in documentation
So can you suggest how i can correct this?
Thanks you for any info

Answer 1

Thanks, i actually found what is the problem. Cause for corruption was incorrect library method for converting from java byte(values from -128...127) to unsigned powershell byte And in hex redactor i`ve got int(8) representation, which is corresponds, if check in powershell(uint) bytes are shown correctly Thanks for help