Printer tones

Thursday 26 February 2004

Speaking of clever techniques using unorthodox channels of information: When I was in college, my best friend from high school came up with a novel way to identify his print-out in the computer lab. It was a large room full of terminals, with a DECwriter dot matrix printer at one end. Students could print to the printer, but there was no good notification system that the print-out was done. You had to wander over after a while and hope that it was ready.

The dot matrix printer made a buzzing sound from the wires in the print head striking the paper. So my friend ended his files with patterns of increasingly tightly spaced vertical bars:

|  |  |  |  |  |  |  |  |  |  |
| | | | | | | | | | | | | | | |

When the file was printed, the typical buzz of the printer would be interrupted by a distinctive rising tone caused by printing the bars. It could be heard across the room, announcing that the file was ready.


In my blog entry on Dancing Bears, I linked to a page on the Computer History Museum web site where someone did something similar with an IBM 1403 printer. They even got it to play songs such as Raindrops Are Falling On My Head.
Another printer related story: in the freshmen dorms we would create printer output to use as wall decoration. I remember generating pictures using our names plotted with mathematical functions down the page. One time I broke the graph generator code and it produced a nonsensical mess. A graduate student and freshman were standing by the printer while I waited nearby. The freshman saw the output and asked "what's that?". The graduate student responded, "Oh that's output from some complex modeling program" and then went on to imagine what it might be showing. When the printer was done, I walked up, picked up my printout without saying a word. I so wanted to say "actually, it's just a bug in my crappy wall art program" but I preferred the image that I was doing "complex modeling" ;-)
The folks at the Symphony for dot matrix printers project are taking that hack to the extreme.
This is tangentially related: you know the noises that scanners make when they're warming up? Someone I know hacked one so it plays Beethoven's "Ode to Joy" when it starts up. Very distinctive ;-)

Add a comment:

Ignore this:
Leave this empty:
Name is required. Either email or web are required. Email won't be displayed and I won't spam you. Your web site won't be indexed by search engines.
Don't put anything here:
Leave this empty:
Comment text is Markdown.