counter datasheet with circuit to use a 32.768Khz crystal: http://www.datasheetcatalog.org/datasheets/90/109006_DS.pdf
interfacing to a 7-segment decoder: http://www.thelearningpit.com/lp/doc/7seg/7seg.html
4511 datasheet: http://www.datasheetcatalog.org/datasheet/philips/HEF4511BN.pdf