Posted by susam 10/27/2025
I wonder what was it like to go through that timeframe, as the management and the employees, where the floppy disks were becoming obsolete. Did they purposefully took the decision to not pursue CD, flash memory market? Or was it just a shortsightedness of the management where they fell behind and eventually had to exit that market?
Of course 3M still managed to be successful and today it is one of the big market cap companies...
You could say that 3M doesn’t make the things you use every day; they make the things you use better.
Things like- not the asphalt shingle, not the granules on the asphalt shingles, but a COATING ON the granule on the asphalt shingle that provides weather protection.
Or, not the memory foam mattress, and not the liquid precursors that are combined to create the foam in the mattress, but an ADDITIVE to the precursors to the foam in the mattress which regulates/ensures a consistent size of foam bubbles during manufacture.
I expect they left the market because of declining use and the entrance of much cheaper foreign manufacturers. I expect they didn't enter the flash memory market as they had no existing manufacturing base for them to build on. They would have had to rebrand another firm's chips and circuit boards.
No more tape storage, no more market for 3M.
Drives which do skip indexing (Like Apple's Disk II) use the actual data on the disk for indexing. Each sector header has a track/sector/head ID, allowing the controller to know where it is on the disk without the need for indexing.
TBH, I'm not sure PC floppies even use the index pulse for anything other than formatting the disk. Once the disk is formatted, it's kind of redundant information. But it's required by the spec, forcing PC floppy drives to include the sensor.
Unlike hard disk drives that use servo data to decide where to read and write, floppy disk drives generally don't know the angular position of either the drive or the sectors and use an extremely simple algorithm. In a very real way, they work like tape drives except they can freely choose one from a bunch of circular tapes to work on.
When ordered to read a specific sector, the drive seeks to the track requested, and then reads the track continuously until it sees the sector header magic value. Then it compares the track and sector numbers after that header with the requested numbers, and if they match, it waits for the magic value (000000000000000000A1A1A1F{AB}) and then starts reading. The magic number is designed to reinitialize the PLL, and also give the drive electronics enough time to make the comparison and decision of whether to do anything. If the numbers didn't match what was requested, then it just keeps reading until it has received a defined amount of pulses from the motor, usually 2 or 3, at which point it returns an error.
The sectors don't have any defined order on the track. You can do weird things like order your sectors linearly except have one specific one out of order, have multiple sectors with the same sector number on the same track (in which case which is returned on read depends on which you happen to hit first), have a sector with the wrong track id on a track (that gets ignored by normal read/write commands, but can be accessed with low-level ones), index your sectors with a set of random numbers between 1 and 255 instead of sticking to 1-18, and plenty more. All these have been used in various hare-brained copy protection schemes. The drive electronics are too simple to care, they just compare one number with another and do a single decision based on it.