Hello Gradius2, thank you VERY much! My Seagate 7200.11 had the BSY error and is now working again! Just one issue, it happened perhaps only with my setup. I used COM1 and the same adapter as yours, the one for $13.95 from Sparkfun. First I used +5 V from the computer PS to feed the adapter. It didn't work, got no answer typing CTRL+Z (no prompt). Looking on a scope, the "low" (TX line) wasn't going low enough, not even close to zero. So I used +3,3 V from an adjustable power supply and could see that the "lows" were much closer to zero level. It then worked perfectly and I could enter all commands as per your listings. Have you noticed something similar? Muchas gracias y saludos de São Paulo, BR!