Rimmer's alarm clock was a larger, old-fashioned style alarm clock, whilst Lister's was smaller, cube-shaped and more "space age". Like much of Lister's possessions, it had a "souvenir of Titan" sticker on it.
Holly often acts as an alarm clock also, using a partially-muted, foghorn-like sound, or simply by alerting the boys from the Dwarf verbally. Queeg also used his own alarm clock sound which was notably louder than any noise Holly used (and on-time).
Lister's alarm clock has a larger role in the "lost episode" of Series I, Bodysnatcher (reconstructed in The Bodysnatcher Collection) much like the Medi-Bot. Rimmer says that it is cheap junk like most of Lister's things. Here it is revealed that the alarm clock has artificial intelligence, much like the Medi-Bot or Talkie Toaster. In one notable scene at Lister's bedside, it continually tries to wake Lister up, dozens of times, playing Mexican tunes and thanking Lister for buying it. Lister, who is having an exceptionally lazy day, eventually gets so fed up of it that he smashes it up (also much like Talkie Toaster).
- Alarm clock: <Whistling a Mexican tune>
Lister: <grumbling under his covers>
Alarm clock: Good morning, this is your 7 o'clock alarm call. It is now 10.57. This is your forty-third reminder. Thank you for buying me from the Official Titan Souvenir Shop, The Home of Quality Tastes and Craftsmanship.
Alarm clock: I'm sorry, did you say... carry on?
Lister: Stop! I said STOP! Stop, stop, stop, stop, stop stoppity stop stop smegging stop.
Alarm clock: I'll carry on then!
- Alarm clock: Cruel bastard! <after Lister has launched his boot at it>