parsing and accessing floppy FAT filesystem in arduino

having converted MFM pulses to sectors, you may be surprised to know its only a couple lines of code to have a microcontroller access the disk and underlying file structure. we use SdFat library, an SD card interface library that is really good, and subclass it to provide new functions for reading (and later, writing) sectors. then you can just treat the drive like a very small SD card. why does this work? turns out SD cards are pretty much the same as extremely large floppy drives: blocks of data are 512 bytes each, and both are formatted with the same kind of filesystem structure called FAT that was invented in 1977 for floppies but persists to this day. SdFat supports a particularly early and compact version called FAT12 and even does long filenames. now our arduino programs can access files on floppy drives with ease! – video.


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1 Comment

  1. Thank you. I’m rebuilding a replica IBM 5150 and have realized that it’s going to be easier to emulate things than search for original hardware at insane prices. I appreciate you all so much and I will buy the floppy flippy or whatever it’s called if you make a circuit python floppy board. Or if not I will buy whatever you make for arduino because I really want to try to use it with the replica ibm. Please accept my sincere thanks and good will. God bless or universe bless or whatever kind of blessing you accept.

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