Season 1 • Episode 1
Episode Information
Air Date June 1, 2014
Written by Christopher Cantwell
Christopher C. Rogers
Directed by Juan Campanella
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"I/O" is the first episode of Season 1 of Halt and Catch Fire, and the premiere episode of the series overall. It originally aired on June 1st, 2014 on AMC.


Joe MacMillan, a fast-talking sales guy, comes up with the idea to reverse engineer his former employer’s PC, and he looks for the right people to help.

Episode Overview

The story begins in 1983, with a man named Joe MacMillan speaking in a college classroom, guiding a discussion on what computers will be able to do in ten years. He asks questions to find out the computer skills and experience of the students in the classroom. One student in particular, Cameron Howe, gets his attention as she makes statements about computers that show she knows what she is talking about. Joe later finds Cameron at an arcade where she hangs out and tries to learn more about her.

Meanwhile, computer engineer and Cardiff Electric employee Gordon Clark is bailed out of jail by his wife. He is living in a reckless and depressed state because of his failure with a previous engineering attempt. Joe gets on at Cardiff Electric and makes contact with Gordon. He uses an article that Gordon got published in the past to harness Gordon's desire to make computers more advanced.

It takes several conversations, but Joe convinces Gordon to reverse engineer an IBM computer. Gordon explains that most of the parts inside the computer are common but that a specific chip in the computer is the part that IBM actually has copyrighted. This part of the computer is what makes it work successfully. Joe and Gordon work in Gordon's garage and decipher the source code for the IBM computer.

Even though what they are doing is illegal, Joe has already anticipated some legal loopholes. Cardiff Electric's attorney figures out that the company can reverse engineer their own computer system if they meet certain criteria. One of these criteria is that they have to keep Joe and Gordon on the project. The other criteria is that they have to hire an outsider who has no prior knowledge of the project.

Joe recruits Cameron Howe to be the "outsider". The attorney for Cardiff Electric asks Cameron questions that are necessary to meet the legal requirements. He nods his head "No" to guide Cameron to answer "No" to the questions.

The executives at Cardiff Electric discuss IBM coming in and insist that everyone keep their stories straight. The episode ends with a group of IBM executives showing up at Cardiff Electric, with Gordon asking Joe what he is trying to prove.

Cast & Characters

Joe Macmillan played by Lee Pace 10 episodes Season 1 

Gordon Clark played by Scoot Mcnairy 10 episodes Season 1 

Cameron Howe played by Mackenzie Davis 10 episodes Season 1

Donna Clark played by Kerry Bishé 10 episodes Season 1 

John Bosworth played by Toby Huss 10 episodes Season 1

Joanie Clark played by Morgan Hinkleman 7 episodes Season 1

Haley Clark played by Alana Cavanaugh 7 episodes Season 1

Cardiff Engineer played by Gregory Hunter 6 episodes Season 1 (Uncredited all except Landfall #6)[citation needed]Barry Shields, Esq. played by Mike Pniewski 5 episodes Season 1

Nathan Cardiff played by Graham Beckel 3 episodes Season 1

Actors of Special note:

Per IMDb: Joanie Clark played by Maggie Elizabeth Jones 1 episodes Season 1

Haley Clark played by Lillian Ellen Jones 1 episodes Season 1

IMDb lists sisters Maggie Elizabeth Jones and Lillian Ellen Jones with credits for episode 1 in season one (I/O), but ALSO lists Morgan Hinkleman and Alana Cavanaugh (above 7 episodes each beginning with I/O) as playing the roles of Joanie Clark and Haley Clark.

AMC[1] makes no mention of Maggie and Lillian, listing only Morgan Hinkleman and Alana Cavanaugh for 7 episodes starting with I/O. AMC is the shows producer and should know who they paid, and IMDb data sources and accuracy are defined here[2] .

Which is correct?

Please go to The Maggie and Lillian Jones Mystery Page to view or participate In the search for an answer!

Featured Music

  • Boomtown Rats - “Up All Night” (1981)
  • Creedance Clearwater Revival - “Lodi” (1969)
  • XTC - “Complicated Game” (1979)
  • The Clash - “Magnificent Seven” (1980)
  • Bonobo - “Cirrus” (2013)


  • The episodes title, I/O, stands for "Input/Output". An "Input" is the data received by a computer or related system, and the "Output" is the data sent from it.
  • Before the official series premiere, this episode was made available on AMC's Tumblr page on May 19th, 2014. It was the very first TV series to do this.

References, Footnotes and Citations

  1. Cast and credits for HACF - I/O episode 1 on
  2. IMDb defines its sources of data, consistency checks, review process and likelihood of error.
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