BBC floppy drive config for IBM PC compatible ?

I’m trying to find a reliable floppy drive for dumping floppies with my SCP card and I have a double floppy drive case that seems to be for BBC systems. They're Mitsubishi model M4853-342M drives.

The drives were connected with a non twisted cable and in the back of the enclosure there’s a switch to select between 40 and 80 tracks.
I tried to use a twisted cable and configure the drives as 2x5.25, 360k on my Windows 98 PC but I can’t access the drive (i/o error).
I suppose there are jumpers to change but I’m confused by all the possible parameters.

1) can these drives work on an PC ?
2) what would be the jumpers configuration ?
3) is there any use for the 40/80 switch when using the drives with my SCP card ?


  • Uh... those are quad density (720k, 80 track 96tpi) drives.

    You sort of can use them on a PC, but not to read 360k disks. DOS/BIOS won't know it needs to double step like a 1.2mb drive. Also, disks written in these drives will not be readable in genuine 360k drives due to narrower head width. (If you connect it to a PC, tell it it is a 360k drive, then use a dynamic formatter program like NFORMAT to format quad density 80 track 720k disks. Again, you can NOT use DOS to read 360k disks.)

    I don't know if the SuperCard Pro software knows how to handle those. If you can convince it to double step, you technically should be able to image 360k disks with it.

    I have one of those in my Eagle 1600. I have had it hooked up to my Kryoflux before. It works.

    If it was connected by a flat cable, make sure to change the drive select jumper on each drive to "1".

    Not really crazy about Mitsubishi drives. I have two Mitsubishi 360k drives, and the second head on both of them has failed. The quad density one worked OK.
  • @SomeGuy I see. So I guess it would be a good candidate to dump Dec Rainbow floppies which are 96tpi one sided, given that the SCP recognises it, correct ?
  • Yes, those should read the rainbow disks just fine.

    The main thing is the SCP software - it trys to figure out what drive to expect based on the media you selected. It is inconsistent about if it recognizes the TPI settings in the menu. So, it depends if you can find a combination that works right.

    Just remember to keep the heads clean, and carefully inspect the surface of any disk you have not tested yet before ever putting it in to a drive.
  • Thanks very much for your advice! I will make some tests during this weekend.
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