Pin Displays

Rigana frowned. "I'm telling you, I can't describe to you what I feel when I channel magecraft through it. It's too complex. All I get is a jumble."
The power-engineer across the desk shook her head. "Try again. There's got to be something here you can see that we can't, from the outside. Whatever magic-eye mumbo you call it."
The wizard gave the other a look. "The mind's eye. And while this may be magical in nature, it's not omnipotence. All I see with my mind's eye is an endless cascade of gearwork. I can describe it only in generalities. Imagine if I told you to describe the crashing of a wave. There's only so much you can say about it without drawing a picture."
The engineer pushed a pad over with a quill and inkpot. "If that's all you need, here, draw whatever you need."
"Literal minded, aren't we?" Rigana gave a thin smile. "It was only an analogy. I cannot help you. Call me a fool if you like, but it is simply far too complicated a mechanism for me to even begin to draw out or describe. But here is what I can do." Rigana placed her hand on the Pin Display, and the gears and cogs began to churn slightly. The pins along the side had their pattern adjusted, reading out the word 'idiot'.
The engineer stared at the Display, mouth agape. Rigana shrugged. "That was just me pushing the pins to that orientation magically. And that's all you'll get out of me."

Utility

The original Pin Display is a mechanism that fits on a large table or desk, featuring a grid of retractable pins along its side, twelve by two hundred and seventy (three thousand two hundred and forty pins in total). The other side of the mechanism features an input slot for specifically patterned Playback Cards. When a card is read, the pins rearrange themselves in a pattern to generate words. The lettering is made visible in two rows of approximately eighty characters in each row, with the patterns of pins retracted and pushed out to form letters, when viewed head-on. 
While thought of as merely a curiosity when first discovered, the removal of the shell of the Display revealed cogwork on a level of complexity utterly irreproducible by standard modern practice. The parts used in its construction are simply much smaller and finer than the standardized parts mass-produced for Power technology purpose, and arranged in such a compact fashion as to defy belief; when clutched into a power plate, the actuators move in a way that would ordinarily cause interference and impaction between the components, but the design of the mechanism perfectly times all motion such that no component ever impacts another. 
Not long after its discovery, speculation occurred that the Display could be used in a *live* fashion, meaning that a sufficiently long punch-card could be fed into the Display, allowing for a sequential series of words to appear over time (or, in an ambitious mode, any arbitrary set of shapes). The appearance of this thought in a journal prompted a major push to attempt to replicate the inner workings of the Display, resulting in the creation of inferior copies - a copy of the Display, with only about a hundred and fifty pins (ten characters, barely enough to create a single word) requiring a room-sized arrangement of rods and cams, with all the attendant frequent breakdowns and maintenance. The original Pin Display has not required any maintenance or upkeep whatsoever, though its handlers at the Academy treat it with extreme care.
Pin Display copies are used as signage for wealthy consortiums, who make a great show of updating the visible text on the display on a daily basis, to the admiration of Power technology enthusiasts.

Manufacturing

Only one manufactory has the specialist knowledge required to even make inferior copies of the original Pin Display, and production of a new Display costs a fortune, comparable to the cost of a number of doses of Oreichal.

Inventor(s)

The inventor of the original Pin Display is unknown. Whoever they were, they must have had access to a workshop capable of ultrafine machining and precision when constructing the cogwork and actuators of that display, and a level of genius that surpasses that of any known Power-engineer working today, in terms of drafting the cogwork plans at this level of complexity. The Principality of Etoile at one point tasked a Magistrate to attempt to uncover the inventor of the original Pin Display, to no meaningful result.

Access & Availability

The original Pin Display is unique and one of a kind, and is stored in a vault at the Academy for intensive study. The lesser versions of the technology, significantly bulkier and far more prone to breakdown, are produced and commercially available, though only used by the wealthiest consortiums for signage (and a display of wealth, besides).

Complexity

Although similar to other technologies based on Playback Cards, such as the Floor-Box and the Powered Transcriptor, Pin Display based mechanisms are by far the most complex constructions of Power technology ever made. Each pin is directly actuated through a rod mechanism of tens of parts; a fully assembled Pin Display can consist of anywhere between ten thousand to a hundred thousand finely worked components, the failure of any of which can cause catastrophic failure of the overall machinery. The original Pin Display has never been disassembled out of a fear of inability to reassemble it - its complexity is likely an order of magnitude higher than anything any Power-engineer has ever made.

Discovery

The original Pin Display was discovered in a disused storeroom of The Academy of Etoile in 722, along with a matched set of punchcards. While the exact workings of that original Pin Display remain unknown, lesser imitations of it have entered manufactory production, though not nearly as impressive in result.