Someone else might have been me, and i had assumed it was I2C given the ref= erenced pdf. I dunno, a non-inverting TinyLogic gate or inverting one iff 3= V uart out can be inverted. Sorry about that. Joe W --=20 Sent from a cloud with K-9 Mail. Please excuse my haziness . Harold Hallikainen wrote: Following up on what someone else mentioned, a pin can be used as an open drain output by driving the TRIS register instead of the PORT or LAT register. You set the PORT or LAT bit low. When TRIS is low, the pin is pulled low. When TRIS is high, the pin floats. If the pin has a 5V tolerant input, it can be pulled up to 5V, making this a 5V output. But, I think I recall the original problem being a UART interface. Since you can't make the UART drive the TRIS bits, that would not work here. In that case, I still think the 74HCTxxx is a good solution. Harold FCC Rules Updated Daily at http://www.hallikainen.com - Advertising opportunities available! Not sent from an iPhone. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .