Arduino Nano Floppy Emulator For When Your Disk Is Not Accessible

Among the plethora of obsolete removable media there are some which are lamented, but it can be difficult to find those who regret the passing of the floppy disk. These flexible magnetic disks in hard plastic covers were a staple of computing until some time in the early 2000s, and their drives could be found by the crateload in any spares box. But what about today, when there’s a need for a real floppy drive and none is to be found? Enter [Acemi Elektronikci], with an Arduino Nano based floppy emulator, that plugs into the floppy port of a PC old enough to have one, and allows the easy use of virtual floppy disks.

Aside from the Nano it has an SD card and associated level shifter, and an SSD1306 i2c screen. Most of the Arduino’s lines drive the floppy interface, so the five-button control comes to a single ADC pin via a resistor ladder. He freely admits that it’s not a perfect cycle-exact emulator of original hardware and there may be machines or even operating systems that complain when faced with it, but for all that it is a useful tool. One of the machines that may have issues is the Amiga, but fortunately there’s a fix for that with a Raspberry Pi.

15 thoughts on “Arduino Nano Floppy Emulator For When Your Disk Is Not Accessible

  1. Fantastic. One question: is it possible to make the virtual drive faster than a normal drive? if not, I presume that you can at least save time by always sending data at the max bus speed, i.e. removing any delays such as head moving from track to track?

    1. yes it will be send at a fast speed since there is no delay in reading the data BUT that might be problematic if they have added in the software some kind of DRM that reads the empty sectors or timing of the load to check for disk authenticity

    2. According to the page it’s slower then the real deal (most likely fixable with better code, or faster micro)

      But these floppy drives didn’t have a “controller” built in, they just give out signal data as the disk is spinning, including an index pulse to indicate the “start point” of the rotation. So you might be able to fake faster spinning, but at a certain speed, the controller on the other side will most likely give up.

  2. This one has a screen, which is of great help in comparison of other emulators which have only buttons and two-digits display for the floppy selection. Now just iron the timings out with some assembler routines and make a user-selectable compatibility mode / options, and it should be the best-cheap floppy emulator one can whip up.

  3. “but it can be difficult to find those who regret the passing of the floppy disk”

    If you say so.

    I wouldn’t use floppies for anything today because obviously their storage space is far too small. But I do miss having a removable media that I could save something to and be pretty close to 100% confident that when I return to load it again it will still be there. After floppies I had so many CDRs go bad sometimes only months after burning them. More recently it’s been USB sticks and they just randomly stop working. My understanding is that’s because they are built with cheap oscillator crystals. I guess I could replace the crystal but really? Maybe SD cards are better. I haven’t really tried to use them that way. The new ones are so small though sneeze and you might never see it again.

    The only good way I know of to back anything up these days short of giving in to the cloud is to buy an external hard drive. It’s effective but kind of pricey.

    And I know. Some people here claim that floppies were unreliable. I just didn’t share that experience. I only ever had one go bad and I know that I left it out on a messy desk for years then it spend a couple years in the bottom of a box of stuff that didn’t get unpacked from moving. No doubt it was jostled and smashed by the things in the box. What should I have expected? I think that’s probably what the people who say they were unreliable did. They probably stuck them in the bottom of a school bag full of books or something. I don’t think that’s a fair test. It was never exactly hard to get a nice hard case to put one’s floppies in and keep them safe. Today we would print that.

    So, yah. I miss floppies. I miss them in the sense that they were useful back when we had smaller files to store. It’s not like I would want to mess with a 1.44MB or less media today.

    1. And they were so much better than using cassettes.

      Most people never experienced that transition, coming later. I guess there’s also people who started with computers that had hard drives.

      My refurbished computer, bought in 2016, is the first “IBM compatible” I’ve had that had no floppy drive

    2. makes me wonder how much bandwidth can be squeezed through the IDE port of the ISA bridge on my old computer (IDE is ISA with two pre-decoded address-lines; for more then one drive andor register) i know IBM-PC is 3.77 MHz but what about a dual-core pentium4 @ over 2 GHz?

  4. I’m a little confused about MFM support and no FM support, but the GH page says it doesn’t support DD disk images? “fddEMU is based on MFM encoding which is used by HD (High Density) disks so there is no DD (Double Density – FM encoding) support as of now.” Pretty sure there are MFM DSDD disks

    1. From the GITHUB page:
      fddEMU uses MFM encoding (used by HD and DD disks) so there is no FM encoding (used by SD disks) support as of now. But it is possible to implement FM encoding.

  5. Hard plastic covers? Bah! Kids!
    During my PhD I was still using _floppy_ disks, 8″ ones, in fact.
    Admittedly by 1992 this really was feeling anachronistic, but nobody had really noticed that the X-ray analyser was actually a minicomputer. It looked so unlike a PC that nobody had felt the urge to replace it.
    I am not sure, at this remove, what it was. I think something from Data General.

    1. I caught that, decided it wasn’t worth mentioning. I still have a bunch of 5.25 inch floppies, but haven’t written to one since 1994.

      Computer growth was never linear, so of those who experienced “floppy” disks, more experienced 3.5 inch than larger ones.

      And what about the poor suckers who bought smaller drives before 3.5 inch became the standard? Some of those were still floppy, and some were 3 inch. Good luck keeping that equipment going.

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