----- Original Message ----- From: "Harold Hallikainen" Subject: Re: [PIC:] serial port dilemma - design advise requested > You could try "open collector RS232". Have a diode with the cathode That was my knee-jerk reaction, but then I thought a minute and figured out that I'm an old fogey. Probably should be open drain in this century. (But hey, open collector still works, and it works well). In the radio world, we use this to connect a PC to multiple radios. Google for "Icom CI-V" for examples. 72/73 de WB8RCR http://www.qsl.net/wb8rcr didileydadidah QRP-L #1446 Code Warriors #35 -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.