this thingie? Unfortunately the 48T02 is a TOD clock and calendar as well as NVRAM, so there's no suitable SmartSocket to replace it. The registers have to be at particular places and use a particular protocol too. Just got the data sheet and the Dallas DS1642 is a direct form, fit and function replacement for the MK48T02(B). It says so right at the start of the sheet. Cheers, Lee. ---------------------------------------------------------------------------- ---- This email is intended only for the above named addressee(s). The information contained in this email may contain information which is confidential. The views expressed in this email are personal to the sender and do not in any way reflect the views of the company. If you have received this email and you are not a named addressee please delete it from your system and contact Merlin Communications International IT Department on +44 20 7344 5888. _____________________________________________________________________ This message has been checked for all known viruses by Star Internet delivered through the MessageLabs Virus Scanning Service. For further information visit http://www.star.net.uk/stats.asp