More Microprinting

I’ve been experimenting a bit more with the thermal receipt printer I bought recently. Inspired by Tom’s daily digests I’ve been trying some of my own.

Microprinter testing - font A Microprinter testing - font B

You only get 48 characters per line using the default font. The alternative font (font B) is much denser, with 64 characters per line. The second printout is only about an inch longer than the first one, yet has twelve additional lines of content.

The barcode at the bottom is a sort of physical permalink using a Code 39 barcode. I’m thinking that each daily digest could also exist in a (private) blog, and a barcode (complete with text date stamp) could be a handy way in. If you’re using this code, or something like it, you could do this…

printBarcode("/2009/02/22/", barcodeModeCODE39);

I used EvoBarcode Scanner to test reading it back in.

Barcode scanning

More ideas for a daily digest:

Tonight I hooked it up to Twitter. Every minute to checks to see what my contacts are saying and prints whatever is new since it last checked (usually 2 or 3 updates).

30 minutes of my friends’ twitter updates equated to five feet of paper. I don’t think I’ll be running this all the time but it does feel reassuring to have it whirring away in the background.

Another use of the Microprinter: printing books. I took the text of Cory Doctorow’s Down and Out in the Magic Kingdom (mainly because I can). It has over 47,000 thousand words, and if you print it at 64 characters per line on standard 80mm thermal paper it’s about 60 feet long.

Printing a book Printing a book

Printing time: about 40 minutes (pausing briefly after every paragraph to let the printer catch up). Rolling it back up again took nearly as long.

At Nick‘s very cunning suggestion there are perforations at every chapter (as well as every sub-chapter, which the ASCII text denotes using a ‘#’ character on its own). Together this divides the book into 59 perforated segments which are about 30cm long on average. Rather than needing a bookmark I’ll just tear off the sections as I finish them.

It’s a portable, recyclable, tear-and-shareable book.

8 replies on “More Microprinting”

  1. Think the daily summary could be really useful- might stand a chance of remembering birthdays and anniversaries, and a traffic report for choosing a route to work would be very handy.

    I would need a reminder somewhere to pick it up though!

  2. Roo, it would be nice to see a pbmto…, or pgmto… program if any of them support grayscale, to fit in with the other netpbm programs. Then it would be trivial to use the other parts of netpbm to produce a dithered black and white image. wget -qO- http://…jpg | djpeg | ppmtopgm | pgmtopbm | pbmto…

  3. I have begun to write a bit-mapped image printing program for the (very similar) Citizen CBM 1000. So far, I’ve only done 432-pixel-wide images, for the very sound reason that I only have 58mm wide paper! 80mm wide paper will allow 576-pixel-wide images. Initial test run shown here.

  4. Now this I like. That’s relatively portable for a book, and presumably quite cheap to produce. Now you just need a better way of rolling it up and a convenient way to use it to read from, perhaps some sort of scroll like arrangement with spindles, maybe clockwork style springs, so it would roll past by itself as you held a button.

  5. John: excellent stuff. I have not got round to adding image support yet, but was going to attempt to decipher the manual later today. Any tips, or example code, gratefully accepted.

    Kyb: very cheap to produce. No ink to consume, and if you buy thermal toll rolls in bulk they’re almost free. I like the idea of a spooling device for reading it, but I was imagining just pulling chunks off by hand, keeping the bits I wanted to keep, making notes in the margins, etc.

    The most painful but was rolling it up after printing. If the printers motor could be made to run backwards, it would be really easy to suck the book back on to the roll again. Hmm.

  6. I love the scroll-book idea. I now have a reason to get into this thermal printing thing. Plus, if a few of us have them, I’d really like to set up a round robin game of Exquisite Corpse.

  7. Hey roo, this is fantastic im trying to do it myself but struggling. is there code for twitter printing? or something you based it on. thanks for all your help already.

    thanks max

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