Hi, GPIB is standart and you should look for 488.1 and 488.2 specifications. The first should be for "wire-bus" specifications. About 8 years ago, I saw solution based on 8051+8255, because the chips from National were not easy to get at that time. So believe, 17C756 can do all the jobs and little bit more. Andrej _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use mailto:listserv@mitvma.mit.edu?body=SET%20PICList%20DIGEST