And she will make her way out and up the mountain, pulling her cart behind her. Eventually, she reaches the programmers' entrance, and hops up on her cart to reach the call button.

It only takes a few minutes for an elderly Crafter on a small walking chair to come out to meet her; he's glad to meet her! She can come right in; he hears she's interested in setting up a new satellite location and maybe adding some complicated things to the machinery here?

"The main thing is that I have 40,000 books from my world to contribute to the library. I could just work through making disks for all of them, but my world has much denser information storage technology available, as you might have guessed from the fact that I have so many books with me," she explains, following him in.

"So I thought it would make more sense to design and attach an adapter that can read from my storage directly. The member of the formatting team that I talked to thought that it made the most sense to use a satellite location connection for that, since they're already designed to stream the content of books."

"I also have some ideas around piggybacking on the library's infrastructure to send messages -- the formatting team-member suggested creating devices the same size and weight as the standard book cylinders, but capable of reacting dynamically to input. On my way up the mountain, I realized that you could do the same thing with just a satellite connection by hijacking the origin routing information to let multiple book 'requests' get concatenated together to form a larger message. I don't know whether you want to permit that, but if I could get an additional contiguous block of unallocated book codes, I could set it up to receive messages from anyone with a library terminal, which would be really useful to me in my broader project of trying to make people's lives better by introducing some of the technology from my world."

Forty thousand books is pretty amazing, and enough that they'll want to add an extra digit to the book encoding; if they're doing that anyway it won't be much extra overhead to add several. He's not quite sure what she means by 'dynamic' there, though - usually when people propose something like that they mean something like the more interactive machines, where the user would be able to put in a code, get a little bit of information back from the machine, and then put in another code to get a little more information back, and the library is really not optimized for that, they're optimized for situations where putting in one code gets the user a lot of information and they aren't especially likely to make another request right away.

"So I definitely understand if this use case isn't something the library wants to support, but the key thing I'd like to be able to do is say 'here are some instructions for how to use your existing library terminal to send me short messages', so that I can collect feedback and information for my technology rollout," she explains. "Crystal people and crafters seem pretty similar all things considered, but we're still aliens, and I lack a lot of your instincts. Which means that I really want to make sure and get feedback from people, to try and minimize the number of mistakes I make."

"That use case could be achieved in a few different ways, though. One way would be to have a book-shaped-device that can go to a book-reader, send some content through to a person's terminal, and then capture further output from their terminal and remember it, so that when it's returned to its book-storage it can convey the message that way. Since my world's technology can be miniaturized really well, you could get a quite complex interactive experience that way, without causing any more traffic through the library as a whole. The downsides to that approach are that it doesn't work through a satellite link, and you'd need some small modifications to the book readers to support capturing input from the connected terminal."

"The other way lets people send messages encoded into a sequence of book requests, which would cause more general traffic through the library. The traffic would be more request-heavy than existing traffic, but I'd still expect it to take up less total bandwidth than conveying a book entirely over a satellite-location link. That might depend on how heavily asymmetric satellite-location links are, though."

"And, once either of these systems are in place, other people could use it as a faster and more reliable way to send letters, which might be of general use."

General traffic is usually the sticking point with this kind of thing; there's a real tradeoff between letting any given person use the library more heavily and letting more people use the library and get their books in a reasonable timeframe, and they prefer the latter. But something that was mostly handled like a regular book but did more complex interaction with an ansible through a specialized reader seems like an interesting upgrade that wouldn't be likely to cause problems, and if it's possible for them to act as a mail hub that way that would be amazing.

"That makes sense! In that case, we should probably talk about what changes would need to be made to the readers, and probably also how the technology actually works. I'm happy to provide maintenance for and construct copies of my technology, but in your place I would probably want to know how it actually works before integrating it into the library," she remarks. "I have textbooks."

"For the specialized readers, I was imagining a system where an 'interactive' book starts with a special character that tells the ansible to redirect input back to the reader. Then inputs from the ansible go to the reader, and each marble gets rung next to the book. The book can react to the sound, record the information for later, and change its shape to change what characters are printed in response to the sound. We probably also need either a second special character which tells the reader to stop rotating the book until a response from the ansible has arrived, or to design the books in such a way that they can send null characters until they get a response, without the reader reaching the 'end' of the book," she elaborates. "You're probably the expert on the best way to modify the readers, though. The technology I'm planning to use for the interactive books can react to or produce sound or safe invisible light easily, and can be made to change shape or react to touch with a bit more difficulty."

"And we probably also want to add some kind of timer-based return-mechanism, so that if someone abandons their terminal or the interactive book breaks, the reader isn't completely monopolized until someone comes to unjam it."

"On the book-storage side of things, I can provide a book-storage machine that talks to the interactive books with safe invisible light, to get the information off of them and put new information on them. That, combined with the book-storage machine being able to read the return address code off of the request, would let you set up a messaging system where someone inputs a letter into an interactive book, it rolls back to the storage, and gives the letter to the machine. Then later the recipient can request an interactive book with all of their messages from the machine."