png2imagewriter

Converts PNG images into appropriate gibberish to drive an Apple Imagewriter dot-matrix printer

Requirements

• Ruby 2.something
• A USB serial adapter
• A serial printer style null modem adapter
• An Apple ImageWriter (tested on a 15”, a II should work although in 72DPI mode, dunno about an LQ)

Installation

• Prepare an image; it should be monochrome (1-bit), and the height and width should be multiples of 8. (There's a TODO to take arbitrarily sized images.) The ImageWriter/ImageWriter 15 run at 72 DPI, so resize the image accordingly.

• Figure out where your USB serial adapter shows up under /dev; it’s usually something like /dev/ttyUSB0.

• Set the baud rate of the serial port to 9600 baud (unless you've set the printer to something else; 9600 is the default. On Linux, this looks like

stty -F /dev/ttyUSB0 9600

• Clone the repo to a directory of your choosing
• In that directory, run

ruby src/png2imagewriter.rb FILENAME > /dev/ttyUSB0

Enjoy several minutes of screeching.