Probably the most boring of the interfaces in the story (from an interaction design perspective, rather than an ethical one), these are monochrome monitors showing feeds from hidden, closed-circuit television cameras in places around the castle—including places you’d expect to be private.

Magenta and Riff Raff watch Janet’s bedroom from the laboratory.

Magenta and Columbia watch the laboratory feed from a castle room.

Riff Raff lets Frank-N-Furter know that Rocky has escaped via the monitor in Brad’s room.

Dr. Scott appears at the front of the castle as seen from the laboratory monitor.
The monitors are unusual for being octagonal, but this looks like a frame on a 4:3 television, standard for the mid-1970s. Note that the show that made this treatment much more famous was Battlestar Galactica, which would air 3 years after this movie’s release. (Another potential influence?)

I’ve got to keep control
What on these interfaces can they control? Look above and you’ll see that the monitor in Magenta and Columbia’s room has a single dial in the upper right. We never see it in use.


The one interface we do see in use is the arm to the right of the monitor in the laboratory. It reminds of me of a slot machine arm, but when we see Janet and Riff Raff operate it, they manually pull it down and return it to the upright position. So it lacks the spring-return behavior of slot machine arms. And as we’ll see with the Sonic Oscillator in the vivification post, there are levers on this panel that stay in place. No, it seems to be a loose, positional lever, and the raised and lowered positions do…something…but it’s unclear what.
Such arms would most befit two states, because the extents of the range are easy for a user to achieve. But there are more than two states, even if we just look at the functions in the film.
- How to turn it off and on? (We see the laboratory monitor off and on.)
- How to change the channel to view other feeds? (The laboratory monitor shows both Janet’s bedroom and the front door feed.)
If this was a real-world interface, we’d additionally want to know…
- How to control the volume?
- How to control the gain? (For a brighter or darker image, as needed)
- How does the camera signal that it is on and recording?
- If the cameras can be aimed, how?
I’m sure there are more I’m not thinking of. Two inputs is not enough. It’s easy to imagine the lever delivering a floating point value between 0 and 1, like a volume control, but that doesn’t map to the discrete functions needed for the simplest functions of off/on and channel selection.
50 Ways to Love Your Lever
It’s possible that the arm position is not binary up-or-down but continuous, with angles mapped to meanings, and held positions setting the boundaries of input. Like, pull it 3° and hold for a second and that puts the system in the select-new-channel state. Or maybe each of the Transsexual keyboard keys is mapped to individual angles, like A = 85–90°, B = 80–84°, and so on. The user would have to move it to the right angle and hold it there for a second for that character to be sent to the processor before returning it to 90° as an “ENTER” function. This has historical precedent in the Dial Telegraph by Louis Francois Clement Breguet in the mid-1800s. Pictured below is the sending mechanism for such a system, which gives an idea about how it worked.

Dial telegraph by Louis Francois Clement Breguet
But note that the usability in the telegraph is provided by a printed guide below the lever that shows what regions map to what letters, so it’s easy to position and confirm that the arm is in the right spot before pressing the commit control. It would be a terrible experience to try and use this without guides or feedback. It would require too much precision and be very error prone.
With no markings on or near the arm, I can’t backworld this into any semblance of sense or usability. Especially since Janet seems to have no problem using it when she encounters the device.
Before anyone comes at me with, “Maybe Transylvanians have more precision and memory and…”, remember we design for humans, and must evaluate interfaces from that POV.
Orientation
I never felt the lever in action, of course, and the prop is almost certainly long since destroyed, but another side note is that… if the lever doesn’t snap in place at the top, and doesn’t have a spring to hold it there, it’s error prone for it to be oriented vertically. Someone could bump it and cause it to fall down, causing some kind of mischief. If it has to be a loose lever, a horizontal orientation of the control would help remove gravity as a complicating factor.
Differentiation of the set of controls is a next concern, and as you’ll read in a later post, I quite like the horizontal orientation of the Triple Contact Electro Magnet lever. Having two horizontal controls, one on top of the other, isn’t great differentiation, even when the control is tightly chunked with its actuator. If it was sticking with this vertical lever for differentiation, then a spring-return lever would make more sense. n.b. It wouldn’t solve the missing controls problem.
A hint of agency?


There is a curious moment when Dr. Scott first appears on the laboratory monitor. The shot is close up on the monitor, so it’s hard to tell if it was due to some action a character took, but the screen goes from staticky to the channel showing Dr. Scott. Many modern systems do that—think of how Zoom automatically switches to the camera showing the current speaker—but it would take a person doing vigilant technical direction back in 1975.

I’m unprepared to ascribe context awareness to the design of these interfaces, but it would be way ahead of its time if it did. After the close-up shot, a pulled back shot shows Riff Raff returning the lever to vertical. This implies he was there off camera pulling the lever in the first shot, but the film does not show what signal might have had him reaching for it in the first place, or what he did to select the channel where Dr. Scott was shown.
So, in the end, the monitors are a narrative interface, conveying the voyeurism and communication plot moments. Their interfaces are handwaves that enable “character sees thing” beats, and we have to leave them as such.
Maybe we’ll fare better with The Vivification Interfaces (currently scheduled for 15 Sep 2026)










































































































































