Hi From Tunisia ! Last week a got the BUSSY problem on my Seagate ST3500820AS (not recongnised by bios), I thought that the drive was permanently damaged, so i bought a new one. My curiosity prompted me to do a search on the net, then i found this great topic of Gradius2. Now everything works great. I also updated the firmware. I used a generic prolific USB to RS232 converter, and a home made RS232-TTL converter. My TTL converter is the easiest one that i found on the net : just a MAX232 chip, 5 capacitors of 1µF and a female RS232 connector. This is optionnal : I've added 3 leds to check power and trafic on TTL Tx and Rx, one resistor of 1 kiloohm is needed to lower voltage. It cost me less than 3 euros :-) I got the 5 volts from a Molex connector (removed fron an old computer fan) Here some photos and the schematic, i hope that it will help someone. I've made my own PCB, but it is possible to use a perforated PCB. Don't overheat the components ! Nothing more to say except : THANKS GRADIUS2 !!