Hello: I have an old Seagate ST-238R drive. I'm the original owner and it stopped working in the early-90s when I foolishly deleted system files to make room for a football game. (I was 12 at the time). However, I still have the drive and am hoping to get the data from it as it has various writing by me and my family saved on it. I've brought to some harddrive recovery places to no avail. A friend of mine told me about retrocomputing and suggested I post here. I'm wondering if the data might be salvageable and how I might go about extracting it?
The ST-238R shown in the image is an RLL (Run Length Limited) drive and will not work correctly with a standard MFM controller, although it has the same ST506 electrical interface and cabling. To read back your data, you will need an RLL controller, which unfortunately are less common than MFM controllers and might not be easy to find.
RLL is an encoding method that allowed 50% more data to be stored on the same hard drive platter compared to MFM, and allowed for higher data transfer speeds. However, it needed more accurate drive mechanics. Back in the day it was even possible to connect a normal MFM drive to an RLL controller and get 50% more capacity (albeit less reliable).
The fact that there are two edge-connectors on the drive tells me that this drive uses the MFM or ST506/ST412 interface (or related interfaces such as RLL or ESDI). These were used on the earliest of PCs and compatibles, as well as other computer systems of the 1980s. This predates the use of SCSI and IDE (ATA) hard drive interfaces that were common from the 1990s onwards, so your options will be limited. Here are the two main options I see:
Get an old computer / interface card
If you're able to find a suitable MFM interface card, it will most likely be an ISA card, so you will need a computer that has ISA slots to connect it to. Alternatively, there were MFM to SCSI bridge boards, which could allow you to connect the drive to a SCSI card instead. (That means you could use a computer with a regular PCI slot, if you have a suitable card.) This related question has some more details on this option.
Use an emulated interface on custom hardware
Some people have developed bespoke hardware interfaces that can connect directly to the hard drive (emulating the computer) and image its contents, or connect to a computer and use such an image to emulate the hard drive. Two examples of these interfaces are the DREM hard drive emulator, and a PDP-8 oriented board. Neither of these options is particularly cheap, however.
One other thing to consider, in addition to having the correct interface, is whether the electronics are damaged in some way as to cause the drive to overheat.
I've had some success in the past pulling data from "dead" drives by putting them in a refrigerator or freezer and cooling them down to the point where it's possible to get (some) data off the drive before it overheats and stops working.
YMMV. Good luck!