I have a model 8425 (not 8425F) which came with its original controller, a WD1004-27X.

I still haven't powered it up to see if it works though.

I wonder what the “f” implies on the model number

8425 is a standard 20MB "Type 2" drive - If the original machine was a AT/286 machine such as an Epson Equity II+ then it should be readable with a generic WD AT MFM controller, though I haven't personally tried running one of those cards in anything newer than a 386. If the original machine was an XT based machine you may need to find out what the original controller was as XT controllers were not always interchangeable. The 8425F is just an 8425 (3.5" drive) supplied in a 5.25" mounting kit - the specifications are the same.

Mine came in a DTK XT machine.

Thanks for the replies
It was from a epson ax-2 I believe 80286
I’m hopeful that a later mother board will support the controller
Card using the ISA slot. I have the two floppy drives from the epson ax-2 and have been able
Access those drives, no surprises here. The hard drive is a little
Old for me to have knowledge on it. Choosing a controller card is the
First barrier.

Any WD1003-xxx controller should work. The different versions are with/without floppy controller and with/without case, but any should read the drive. It will be type 2 in most bios - 615 cyl, 4 hd, 17 sect. MFM drives do not auto detect.

Wow thanks so much for the info. I’ll purchase the card and give it a go.
Do you think it would be ok to power the drive before I get the controller to see if it spins up.
I heard these drives are very fragile

Could the data be RLL?

musicrepairs wrote:

Wow thanks so much for the info. I’ll purchase the card and give it a go.
Do you think it would be ok to power the drive before I get the controller to see if it spins up.
I heard these drives are very fragile

Yup, and they sometimes like to stick the heads on the surface sometimes.
If it does not spin up, give it some turn when powering up, to give it a sort of "kickstart".
Needs exercise to do this.

So you can check whether it makes any sense to get a controller.

Something to keep in mind when trying to use an MFM/RLL drive with a different controller card than the one that was originally used with it is that, even if you configure it with the exact same parameters, it might not be able to properly read the data on the drive due to slight differences in how the controllers position the tracks or sectors on the drive. MFM/RLL drives are really dumb devices, they rely 100% on the controller card to tell them what to do, and unfortunately not all controller cards functioned identically.

Also, depending on how long the drive has been sitting unsued, MFM/RLL drives are also notorious for gradually losing data over time as the sectors lose their ability to hold a magnetic charge. This can further complicate data recovery efforts.

Thanks for the info. I’ll take the gamble when I can get.
Controller card at the right price. It will be a good learning experience

Dont forget you need 2 special cables to connect the drive.

I already had a MFM drive running in a Pentium. You only have to disable IDE as far as I remember.