Plain ASCII text editor / programmer’s editor

I’m looking for a plain text editor plug-in, with the same text-only editing such a TextPad, or Windows notepad.

By plain text, I mean wysiwyg for text. No embedded formatting codes, no etc bold/underscore, no visual/code editing modes.

The end-of-line code must be Unix style, not Windows/DOS style.

Of course, I mean such an editor used within WP.