I can't find any adapters or secondary connectors, can anybody get me a link to a working floppy controller card that works or possibly a connector that goes from 20 pin male to 34 pin female? I have to work with 5.25 in Apple 2 drives to recover geological survey data, and I have the drive I just need the controller or connector in order to hook it up to my current pc, if it connects through USB that's helpful as well.

  • 3
    The data is on a floppy disk, right? The short answer is to use a Kryoflux or similar device. Commented Sep 9, 2020 at 18:04
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    I’m voting to close because this appears to be a shopping question. Commented Apr 4 at 16:32

4 Answers 4


In short you won't find any adapter that will work for a regular PC controller.

PC's use a different kind of encoding (MFM) from an apple ][ (GCR) so you'll need to get a new controller or use a genuine Apple ][.

I would recommend AppleSauce https://applesaucefdc.com/ which connects over USB to a PC. Other alternatives are Kryoflux and there maybe a few more. Alternatively find a local apple ][ enthusiast.

  • The encoding is actually not holding it back. Even just with software, with a trick a PC floppy controller is capable of reading Apple II disk complete tracks in double density MFM, which is good enough to software decode the GCR. See disk2fdi. But I agree an USB connected device to drive the floppy directly is the best choice.
    – dirkt
    Commented Sep 10, 2020 at 2:55
  • Thanks for that @dirkt I didn't know about disk2fdi.
    – PeterI
    Commented Sep 10, 2020 at 6:32
  • The difference in track stepping between the Shugart bus and the Disk II would definitely be enough to prevent a passive adaptor though.
    – Tommy
    Commented Sep 10, 2020 at 11:50

Your question is confusing because there is not a 34-pin option for a 5.25" floppy disk drive that is directly compatible with an Apple ][ floppy controller card.

This link describes all the various, common, Apple II floppy controllers. They commonly provide either a 20-pin male ribbon cable connector, or a 19-pin female D-sub connector.

I assume you have an Apple ][ with the original Disk ][ controller card. This controller supports a 20-pin ribbon cable connections to a Apple Disk ][ drive, and the cable is normally hard-wired to the drive.

You should check that your Apple ][ compatible floppy drive has either the 19-pin or 20-pin connection. If your drive has a 34-pin connection, then that sounds like a PC floppy drive to me.

  • 1
    Given that PC floppy drives are a dime a dozen, I wonder if there would be any value in an interface that would allow the use of a PC drive with an Apple, subject to the constraints that it wouldn't be compatible with software that uses half-tracks, and most drives would be incompatible with most "flippy" disks.
    – supercat
    Commented Sep 9, 2020 at 15:54
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    The way I read the question is, he has just the drive, and he's trying to connect it to the 34-pin floppy port in a PC. Commented Sep 9, 2020 at 17:56
  • @snips-n-snails: Ah. I'm actually working on a bridge between my Apple //c external floppy connector and a USB port, which I expect should be able to archive Apple [and probably Commodore] disks in about 10 seconds each.
    – supercat
    Commented Sep 9, 2020 at 21:51

EDIT: New answer. See below for old answer.

Another solution that could work, not tested, is to read the floppies with Kryoflux. It is advertized as being able to read the raw magnetic flux of all floppies in PC drives. I haven't tested it and I read that it works but is somehow very complicated but it is an idea. https://www.kryoflux.com/ http://www.os2museum.com/wp/kryofluxing-pc-floppies/

EDIT: I misread the question and responded with the contrary of the question. I keep the answer as it is still more or less relevant.

There were special controllers for Apple II that had besides the 20 pin Apple Interface a 34 pin Shugart interface. Erphi from Germany sold them. I have one and it works quite well. DIP switches allow to set the nummber of tracks 35/40 (70/80), double step etc. You just have to be careful to not use the IBM-PC twisted drive select/motor control cable and setting.


Sometimes you can find them on ebay.

  • Very interesting, though the OP is actually asking for PC hardware to connect Apple II Disk Drives to (or hardware to read Apple II Floppies in general from a PC), so the reverse case.
    – dirkt
    Commented Sep 10, 2020 at 8:53
  • Oops. Oversaw that. Commented Sep 10, 2020 at 16:07

actually, there was a 3rd party apple ][ card that would connect to standard 34 pin floppies. I had (should still have) one if no museums have this.

  • 1
    oops, i missed the comment about the op also Commented Apr 4 at 15:51
  • Could you edit and expand upon your answer a little? Maybe include the make/model of the card, a photo, or link to documentation as a reference? Commented Apr 4 at 17:08

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