Typing raw bytes

[Eli Zaretskii]

Suppose I want to create a file whose contents is a series of certain
bytes.  How would I go about that?

I tried "M-x hexl-mode RET" in a new buffer, but it evidently doesn't
let you insert bytes, only edit existing bytes.

Next I tried "C-x RET f raw-text RET" in a new buffer followed by
"C-q NNN" etc., but the data written thereafter to disk is more bytes
than I typed, because, I guess, "C-q NNN" inserts windows-1255
characters (this is on Windows, where keyboard-coding-system is
windows-1255-unix), and what winds up in the file is their UTF-8
encoding.

The only way I found that does the job is insert-byte, which is not
very convenient.  For starters, it's not a command.

Is there something else I'm missing?  Should I file a bug?