I feel like I'm somehow not asking the right question, or it's somehow obvious to everybody else. I have a Papilio Pro (due to the socz80) and will certainly want to tweak the logic. How am I supposed to do that? I downloaded many gigabytes of stuff from Xilinx (ISE DS 14.7, multi-arch, I'm on x86 Debian) and told it to install. It told me how the tools were going to monitor me and phone home, and by the way I'd better enter my license. Does everybody here have a license? Did I pick up the wrong download? How do people here install/run tools to create new bits based on changing the VHDL? Once I have "compiled" VHDL bits, is it that Papilio-Loader which takes them and feeds them via a ttyUSB port to set up the FPGA? I see that *two* ttyUSB ports come into existence--is that expected? Which one is for which purpose? Thanks much, Andy Valencia