George R.R. Martin visited "Conan" on Tuesday and talked about killing off his darlings in "Game of Thrones."

The author revealed he didn't have any reservations killing off characters years ago when he wrote the novels, but is glad he didn't make the show before writing the books.

"I killed them years ago in the books," Martin said, referring to the many deaths in the HBO adaptation of the series. "At that time we didn't actually have an actor who playing [Joffrey]. Jack Gleeson, who played Joffrey, was actually the nicest guy in the world."

"I think it's a good thing that I wrote the books before we started making the show," he added. "Because when you make the show and you actually meet the actors, then it's harder to kill them...because Jack will be out of a job then."

Conan also asked about Martin's writing style and why the author isn't afraid of getting a virus that will wipe out half of his book. Martin revealed he own two computers and has designated one for web browsing and the other for writing only.

"I have my writing computer, which is a DOS machine, not connected to the internet," the author said. "I use Wordstar 4.0 as my word processing system."

For those unfamiliar with Wordstar 4.0, it is a DOS word processor from the 1980s. Martin explained he isn't a fan of newer word-processing programs because he doesn't want help or need to use spellcheck.

"It does everything I want a word-processing program to do, and it doesn't do anything else," Martin said. "I don't want any help. I hate some of these modern systems where you type a lowercase letter and it becomes a capital. I don't want a capital! If I'd wanted a capital, I would have typed a capital! I know how to use the shift key!"

"Game of Thrones" airs on HBO Sunday at 9 p.m.