Hello, First of all, I'm sorry for asking my question here, I don't have a Papilio, instead I've bought a Mojo v3, and I think I will regret it for a long time... The hardware is fine, it's the support forum that bugs me, almost dead :| Also, I'm still a newbie on FPGA so here it goes: Mojo communicates with the AVR onboard and then with the PC via serial port (http://embeddedmicro.com/tutorials/mojo/hello-world/)I've been using this project as starting point, and want to make a simple change:Input data via serial, and after pressing Enter, the FPGA would return the data again.I think I need a shift register and ram right? or just a big vector?Could someone point me some tutorial or best way to acomplish this?I can only use 8bits with tx_data and rx_data.After understanding this, what I really want is to send a string, have it processed by a MD5 core, and then make it return the hash, everything via UART. Thanks! BTW: After I understand the basics, my intention is to convert this: http://infinityexists.com/videos/fpga-md5-cracker/ To Spartan6LX9, without VGA or PS2 keyboard. Yep, still a loooong way, too much to learn