This one(coral cache) is a bit of a head slapper, but I thought it might come in handy. Laptop (or usb) serial ports are pretty notorious for being stingy on power output. [Roberto] came up with a clever solution. He used a MAX205 (sort of a double+ MAX232) and a singe capacitor to convert the low power serial connection on his laptop to a TTL signal and back again to RS-232. The result is a simple dongle that needs 5v and gives you a high power serial port for those power hungry devices – like [Roberto]’s PIC programmer.