I'd say this is an excellent recipient fot the AT flavor XT-IDE XUB, put inside a repurposed Promise 16bit IDE controller.

Ebay is overflowing with pci boards, which wont work in your 286.

This board will though.

https://www.ebay.com/itm/298230689126

It has an LBA bios on it, but who knows how well it works. You could replace it with XT-IDE XUB, if you have a way to flash eeproms. If not, the stock one should give you >8gb disk support. (Just probably limited to 128gb max)

A 5.25" -> 3.5" bay adapter will let you home a desktop IDE drive in there, but a DOM or an SD->IDE module could concievably be tucked away on a 3D printed retainer, with an ISA slot bracket bolted to it, if you dont want to lose a drive bay,

hi thanks for your message i have a card that was already in it can i use this card to attach a hard drive to it iv taken a picture of the card
the only thing is when it was inserted without any hard drive connected it made my machine not boot at all but im wondering if i have a
hard drive connected to the card will it boot up then

That is an MFM/RLL controller. That is "The original kind" of hard disk controller.

The drives that can live on that tend to be physically large and heavy, slow, have very little storage space (the biggest ones were about 500mb in size), and are 40+ years old.

If you are concerned about the originality of this system, yes-- that card will allow you to have a hard drive connected. You will need to positively identify it from its markings, since MFM and RLL are not the same thing, despite having an identical interface cable. (the difference is how data is transmitted over that cable, and how data gets written to platters in the connected drive. MFM/RLL hard drives are "dumb" devices that just follow orders. All the intelligence is on the card, and the materials the platters in those drives are made of, have "intended for XXX encoding" in mind. AS such, you should not put an RLL controller on an MFM drive, unless you know exactly what you are doing.)

*edit
I have looked up your controller card, and it appears to be this jobbie.
https://theretroweb.com/expansioncards/s/west … 1002a-wx1-ver-1

This is an MFM controller card produced by WesternDigital corporation.
To pair it with a drive, you will need to find a functional MFM disk drive, then initiate a low-level-format to create low-level disk structures on the platter appropriate for that controller card.

Otherwise, if modern convenience is your plan, ... or you would like your 286 to not take 20 seconds to return a directory listing... , I would suggest replacing it with a 16bit IDE controller, like the one I cited. One that has an LBA bios on it, so modern drives can be detected/used.

thanks for the info very interesting yes i think the way to go would be to get the first card you showed in the link if i am to get one

Yeah, thats an MFM controller... There are two ribbon cable connections to each drive. The longer one daisy-chains to all drives, and the shorter one is per-drive.

As you can see two short connectors, that controller supports up to two drives.

And as mentioned, drives were SMALL - for years I used ST-506s(6m) and ST-412s(12m) - these were full height 5.25" factor (afull bay on the XT). More common were ST-225(25m) and another I don't recall the name of which was 40m - these were 1/2 height 5.25" form factor (you could mount 2 in a bay and get a whopping 50m or 80m)

-and those sizes are unformatted bits - actual data capacity was slightly smaller.

Tricky to find a working one these days - and I wouldn't trust it much if I did find one .. I'd get an IDE controller if possible. (at least then you can use a SATA<>IDE adapter - and CF cards are IDE interface)

jude1977 wrote on 2026-06-14, 15:15:

thanks for the info very interesting yes i think the way to go would be to get the first card you showed in the link if i am to get one

The main feature is the presence of a socketted bios.

Otherwise, 16bit IDE controllers are basically all just passive logic, and bus transcievers. Nothing magical that would make one brand better than another.

The bios socket allows for a bios "extension", that can take over the main system's disk controller routines, and provide "better" ones. The reason why this is very desirable for your 286, is because the era those systems were built in, disk drives were all very small and expensive. Support for them was limited to a table of about 30 hard-set "types", and if you were lucky, the system supported a "Custom" type that you could fill in yourself. (but this was not assured.)

the addressing method used by old disk drives is called CHS, or Cylinders-Heads-Sectors. Three numbers that define (ideally), the number of platters, how many heads per platter, and the number of sectors present on each head track. These numbers had hard-set limits on their maximum values, and, combined with some restrictions imposed by MSDOS, result in an unfortunate storage capacity limitation of about 504mb.

The LBA bios on the card I cited can completely take over functionality from this old and limited methodology, and can provide system support for large and modern drives.

When seeking a controller card, you should very much be picky, and look for a card that has such a BIOS socket on it. Even if the BIOS that is currently installed in that socket is old and has unpleasant quirks about it, unsocketting the chip and replacing it with a burned EPROM containing XT-IDE's BIOS will give you a very enjoyable experience. (Again, because 16bit IDE controllers are otherwise unremarkable, and the universal bios they supply will work with pretty much everything out there.)

Not all IDE controllers from the era have such sockets though.

Quite frequently, retro enthusiasts have to find *OTHER* ways to get that universal bios on their systems, such as populating the boot prom socket of a network card with such an EPROM.

I pointed out an IDE controller with that socket present, for your convenience.

thanks for everyone's input ill definitely stick with a ide controller buy the sound of it that seems the best option as stated from you guys

Once you switch to an IDE drive, TRW has a summary of the issues you'll encounter that will dictate whether you can get away with your existing system BIOS to interface with the drive, or need XT-IDE Universal BIOS as an option ROM as suggested above. https://forum.theretroweb.com/t/286-discussion/56/2