I like to be able to read books in other formats (FB2 is a prime example) and use custom readers (e.g., I like coolreader for its configurability). I think neither is an option with Kindle, so I use a rooted Nook.
However, I like Kindle hardware a bit more, so I would probably switch if it can be unstuck from using the Amazon default software choices.
I've jailbroken mine to have custom covers. Instead of famous dead American authors I've never read, I have famous dead physicists whom I've actually read and whom I admire.
I'd love to do this using "pulp" science fiction book covers. I assumed that there was already a tutorial for this, but my Google-fu is weak. Did you use a guide or just DIY? What size/resolution image does the Kindle expect? Is there a filename format or a directory structure to use?
Image format is grayscale 800x600 (bigger for Kindle DX) png or jpg. For best quality I recommend fiddling a bit with the color to grayscale work in Gimp or Photoshop, especially if the image has large areas with soft gradients. IIRC, running a selective Gaussian blur after grayscaling, and/or working the curves tool a bit before grayscaling, will improve problematic images quite a bit. Early models had only 4 grayscales, now they have 16. "Posterize" to 4 or 16 colors after grayscale in Gimp will give you a good idea of how the end result looks.
Some people add their contact details to the screensaver images, so if you lose your kindle your contact details are the first thing someone who finds it will see.
Maybe a better hack would be to disable screensavers since they serve no purpose on an e-paper display and actually cost battery to switch from text -> screensaver -> text.
The better behavior would be to not flip the screen at all and keep it static, using no battery.
As mentioned, I think the most popular use is for custom covers. Recent firmware versions show that Amazon might be slowly working towards this as a feature.
As the guy who wrote this, I don't use any of the addons. Just did it for fun.
Well, the kindle runs essentially Linux so by jailbreaking it you gain the ability to launch arbitrary code! Eg alternate pdf readers, games, ssh, vim and a lot more which can be very useful (especially the off reader KOreader)!
check out mobilereads forums if you want to know more about that, it's a vibrant community.
What I'd like to see is someone get xterm in Tektronix 4014 emulation mode with $EDITOR to run on the Kindle Keyboard. Because e-ink screens are exactly like the old Tektronix vector displays, in that adding a character/line/dot to the screen is much faster than repainting the whole screen. Should make for a much more useable experience.
You can left-justify text, just like in actual books. That alone is reason enough to jailbreak, it baffles me why amazon are so tone-deaf regarding this.
Nice. I wonder if you could do away with the laptop altogether, and just use your phone with the Kindle, maybe with a bluetooth keyboard for the kindle (for some light work on a beach).
Or if there are any other e-ink tablets that run a full linux (cli) or Android?
There are eink readers that are easier to hack, like the Kobo, but they're all limited in that they're e-readers and have the minimal processing power to match. The only full on eink tablet I know of is this one[0] which technically doesn't exist yet. It's fully funded, though, so I'm excited to see if it actually ships.
I can tell you what I'd like to do with my Kindle, that's absolutely worth jailbreaking it.
I use it for my own .mobi files from a variety of sources, including books I wrote myself. I purchased mine and paid to have no advertising on it.
I would roll back to the previous operating system, which did not have advertisements on the homescreen and did not make me navigate two levels deep just to get past subfolders and a 'downloaded' option hiding my own books from me by default, and I would remove its ability to update itself or do anything via wi-fi.
I would just connect it via USB for all file management, and that would be perfect for me.
Needless to say, I'm really frustrated with the 'update' I never asked for OR installed, which has screwed up these things. I am very, very interested in what can be done with this jailbreaking. All the more as I don't wish ever to purchase a book through Amazon again, if this is the direction they're going. And they are, they obviously are.
One nifty trick that I found few people know about, is that you can upload your own .mobi books into the Kindle cloud. Just use the email that they provide to upload PDFs and the like.
Once the books are there, they show in your cloud collection and are available for download, same as Amazon-purchased books. Better yet, you will also get cloud sync across devices for current location, bookmarks etc - probably the most enticing reason to go down this route.
(Not sure if this is helpful to you, if you really prefer to manage files directly via USB. But might be helpful to someone else.)
The first thing I did was to turn off the wifi on my kindle, so I don't have to deal with upgrades or ads. And somehow I can add my own .mobi file to my kindle via usb. I added pdfs I converted to .mobi that way (with some software I found through a google search).
I turned mine into a little status display, showing today's weather (and a few other geeky things, but that's the main one). The combination of very low power usage and readable e-Ink display is great. Also older models are very cheap -- mine was £50 including delivery.
You can find tutorials for doing this all over the place, eg https://www.youtube.com/watch?v=Oel08SDFyIY (not the particular one I used, but he's done a very similar job to mine).
Afaict, it's entirely a technical writeup about how to jailbreak. From the intro: "This document details the steps and thought processes I went through when developing the jailbreak. Ideally this will be a useful map or starting point for anyone looking at the system in the future".
I didn't find any information aimed at users of the Kindle about why they'd want to jailbreak.
I assume gp was talking about the 7th paragraph mentioning "whys" such as epub, fonts, screensavers:
>The mobileread community has done a great job developing extended functionality of the readers. Some of the more popular packages involve an open-source alternative reader with ePub support, a plugin to change fonts, and another addon to enable custom screensaver images.
Not related to this hack, but I did see a post from a guy once that hacked his girlfriend's kindle so the screen saver showed the cover of "Mein Kampf" as a prank.
I was thinking the same thing... I can only think of "bragging rights" or a learning experience.
Although I think this is what makes the (internet) world awesome at the moment. The author sounds like they were mucking around to see how far they could get. Put some thoughts down for others to read and who knows?
Whenever we're recruiting, we always look for interesting things a candidate has done. Something like this will easily get you a first interview...
On stock (and jailbroken) Kindles you can send PDFs or MOBIs to username@kindle.com and have them auto-downloaded to your Kindle. Many people use Calibre[1] (FOSS, win/mac/linux) to sync/manage their ebook collection using this feature. You could easily couple it with Dropbox.
You can also use Calibre to have newspapers/magazines sent to your Kindle every morning. There's tons of recipes for scraping BBC, NYTimes, WaPo or $local_paper, rendering with custom CSS to get readable ad-free version, converting to MOBI and sending to Kindle. There has even been SaaS offerings running hosted Calibre cronjobs with user-provided recipes. Not sure if any still exist.
> On stock (and jailbroken) Kindles you can send PDFs or MOBIs to username@kindle.com and have them auto-downloaded to your Kindle.
That's no good for me because I tend to do a lot of random edits of my epub collection to fix editing errors, replace cover images with better ones, etc. The reason I want Dropbox is to automatically propagate changes like that, not just to transfer files over.
Upstream comment recommends running KOreader on jailbroken Kindle for (amongst other things) syncing with Calibre. I'm assuming this is two-way sync, but I don't know.
However, I like Kindle hardware a bit more, so I would probably switch if it can be unstuck from using the Amazon default software choices.