Steve Russell wrote: > source=http://www.piclist.com/postbot.asp?id=piclist\2002\11\07\023119a > > Call me old-fashioned, but I don't think that you should just connect > the pins together as many here seem to suggest. You should use the > resistor technique described by Scott Dattalo. Without doing so, you > have no way of knowing how the current will be divided by the two ports > and you could exceed the spec on one of them. OK, you're old-fashioned! :-) Seriously, the pin drivers are MOSFETs, which generally don't need ballast resistors when operated in parallel. If one starts to warm up relative to the other because of excess current, its resistance goes up and the current is diverted the other way. -------- To another poster who was wondering about "open-collector" (really open-drain) outputs: You can simulate this, within the voltage limits established by the protection diodes, by setting the output data permanently to 0 and turning the tristate bit on and off. -- Dave Tweed -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads