In SX Microcontrollers, SX/B Compiler and SX-Key Tool, Peter Van der Zee wrote: Hi There; Symmetrical drive means the transistors in the port can "push" (source current) equally well as they can "pull" (sink current). As far as data memory is concerned; not directly, but certainly via software, either parallel (uses lots of I/O pins) or serial uses many fewer I/O pins). Cheers, Peter (pjv) ---------- End of Message ---------- You can view the post on-line at: http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=79341#m79343 Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2005 (http://www.dotNetBB.com)