I am building a digital clock with Nixie tube display for a friend and we have decided that we will not use any components which were not available in 1978 (the year we started work together, me as a hardware designer, her as a software engineer) My problem is that i cannot remember what CMOS chips were available 40 years ago. I am fairly sure that the CD4000 series was established by then but cannot remember if the Texax HC74 series had been released. Anybody got a really good memory or, even better, old data books? __________________________________________ David C Brown 43 Bings Road Whaley Bridge High Peak Phone: 01663 733236 Derbyshire eMail: dcb.home@gmail.com SK23 7ND web: www.bings-knowle.co.uk/dcb *Sent from my etch-a-sketch* --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .