In a message dated 97-12-09 16:42:28 EST, you write: << I am interested in more information on GPS. Does anyone have any good links? >> About a year ago, I looked at gps stuff. I found that Trimble has two nice little books they are willing to give you that discuss GPS and Differential GPS....great introductory stuff. Several companies had small recievers (small is relative...not small enough for my application at the time) and the cheapest solution I found was a chip set from Rockwell that was approx $50US, if I remember correctly. After you get the signals received and coorellated, you still need reasonable power to calculate position and do anything with it. I do not think that the PIC is the right horse for this plow. If you want more details, e-mail me privately and I will dig out my file and try to answer specific questions, but these times are-a-changin' and you will likely find more useful info via a search with your favorite www engine. If you find anything very small (less than one inch square) or very cheap ($30 or less at 100K volume) please let me know, I may be able to dig up my old client and convince them to re-open the project. Mark A. Corio Rochester MicroSystems, Inc. 200 Buell Road, Suite 9 Rochester, NY 14624 Tel: 716-328-5850 Fax: 716-328-1144 http://www.frontiernet.net/~rmi/ ****** Designing Electronics for Research and Industry ******