> Peter, > "RS fliflop"? 74{HCT,LS,HC}74 {CD,MC1}4013 set-reset flipflop (the kind easily made from two NAND gates but better bought ready made - see above part numbers). The 555 solution someone else mentioned should work fine. Peter -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.