Inferior Ruby for Emacs

Hi,

I've recently switched to Emacs for programming in Ruby.

The stock Inferior Ruby Mode (inf-ruby.el) has 2 inconveniences:

1. There's no command history, i.e. M-p and M-n don't work
2. The output of irb isn't read-only, i.e. it can be deleted using the
backspace

Does anyone know how to fix any of those?

Any advice is very much appreciated.

A. Rubio