marginal at best. 232 can run up to +/- 24V, with large transients. The transmission gates won't appreciate that at all. You're better off to convert to TTL/CMOS levels first, then do your transmission gates, or logic based solution inside the buffers. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist