5.25" floppy drive support?

As far as I recall, 5.25" and 3.5" floppy drives used the same controller board and cabling: you could mix either type on the two plugs on the ribbon cable. However, the floppy controller has been removed from most new systems. There's been a serious effort to remove it, because it had an awful programming interface that required very frequent interrupts (one per byte transferred in the non-DMA case, and I think there was some problem that stopped DMA mode being useful) meaning that a lot of CPU power was just being wasted on managing the floppy drive.

I think the market window for PCI floppy controllers was very small, if any. While floppy drives were still useful, there tended to be a controller on the motherboard; USB floppy drives came into existence before on-board low-pin-count/ISA floppy controllers were retired.

I suppose it might be possible to dismantle a USB 3.5" floppy drive and see if there's a connector you could plug into your 5.25" drive instead! It might still not report the right kind of drive to the OS, though.

I would suggest that the most flexible approach might be to get up an ancient machine which supports DOS and networking and can operate with an old floppy drive. I think there were some utilities once upon a time that were designed to copy files from a floppy drive more quickly than would be possible using DOS (they would read the FAT, figure out an optimal sequence to read all other necessary sectors, and then read the sectors in that sequence). If you have disks containing lots of small files, such a program might be able to read the disks a lot faster than would DOS. Some such programs might also have been able to read sectors in whatever order they appeared under the drive head (which could save up to 200ms per track) but I'm not sure.

  BIOS (Basic Input Out System )  Run .

  Insert Key 'Del' or 'F2' When Your System Start

  Bios Menu Writen, How to supported device

  5.25" floppy drive ..  that first screen under . 

 

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