Could use these, in general I like to stick to DIP chips with sockets (and a Zener in this case). Surface mount tend to be a little tricky for some. There is plenty of space on this board. There are DIP “level changers” also, but outfits like Jameco don’t stock them. As a general question, how do people feel about surface mount chips? I currently working on plans for a 80386 RAM board where capacity is an issue. Do most people fee that could solder SM RAM chips to a board. Really would increase board capacity for pseudo-RAM chips. John John Monahan Ph.D e-mail: mon...@vitasoft.org Text: mon...@txt.att.net From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of yoda why not use 74lvxxx logic to interface to the lava board ? - it does the protection and is 5V tolerant - it has been used in propeller interfaces for the same thing and makes the parts count a lot smaller Hi Paul! Thanks! Yes, the 3.3VDC Zener diodes are added after the 100 ohm |