This is a FAQ that describes GPIB programming tips and describes some example programs which may be found on the software CD that comes with the CSA8000.
http://www.tek.com/Measurement/Support/scopes/faq/tds8000.html
You should call Tektronixs and ask the to send you the CD (It should be free). Also the programmers reference in manual would be a good place to start. I don't know if you can get it for free, but you may be able to get Tek to send you an electronic copy.
-Jim
