Data Recovery and Disk Utilities Forum @R-TT

Experimenting with old drive that spins but isn't recognized by bios.
I connected to its serial port (ground, Rx, & Tx). Trying to connect using Putty but no success.
Is there some way I can get R-Studio to scan it even if slow?

No, you can't.

Very few drives even allow reading user zone sectors over TTL anyway. The purpose of that port is to service the drive, fix the firmware, etc.

I think you need to get the drive to a professional data recovery shop who can properly assess it.