http://de.wikipedia.org/wiki/RS-232
http://www.sprut.de/electronic/interfaces/rs232/rs232.htm


http://vikram.eggwall.com/computers/usb_cable/index.html
http://www.mikrokopter.de/ucwiki/HandyKabel
http://bettyhacks.com/wiki/index.php/Interfaces_PC_zu_Betty
http://weldinghamsters.blogspot.com/2009/11/modding-pl-2303-based-usb-to-rs-232.html
http://endless-sphere.com/forums/viewtopic.php?f=2&t=8317&start=30
http://seriousrobotics.wordpress.com/2010/12/05/make-your-own-ftdi-cable-for-about-5/
http://www.hackmeister.dk/2011/01/alternative-programming-cable/
http://sites.google.com/site/brandonselectronic/usbtottl