I was certainly in a similar boat (though a later generation of computers) whereby I found around age 9 that "poking" at a computer (either plugging random things in, or clicking random buttons or keys) enough yielded some interesting/mildly entertaining results. Of course, many times, these results ended with being grounded for breaking something, but nonetheless, the endless possibilities of random keystrokes and mouse clicks seemed to exude some kind of strange primitive allure.

Also, K&R for kids ages 12-14?!