Oops it seems like that should the FM1808 that is a replacement for the DS1230Y. -----Original Message----- From: David C. Partridge [mailto:david.partridge@perdrix.co.uk] Sent: 19 December 2017 13:28 To: 'Discussion of precise voltage measurement' Subject: 3458A NVRAM I'm looking at the A5 board in my 3458A. The DS1220Y and the two DS1230Y NVRAMs have 1997 dates, so should likely be replaced. I *think* the Ramtron FM1608-120-P is a direct "drop-in" replacement in this application for the DS1230Y. Is that right? If so I'll get some in from eBay. Is there an FRAM direct replacement for the DS1220Y-150? Or should I use a FM16W08 on a 28 way SOIC to DIP adapter as per <https://xdevs.com/fix/hp3458a_u4/#fram> Thanks Dave