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Description: Welcome to the floppy cafe! These pages are the lost and sacred texts you've been looking for if you happen to be writing a driver for a 3.5in floppy.
______ | |__| | | () | |______| floppy.cafe home mfm encoding functions troubleshooting Bit Banging a 3.5" Floppy Drive Welcome to the floppy cafe ! These pages are the lost and sacred texts you've been looking for if you happen to be writing a driver for a 3.5" floppy. To learn these mysteries, I bit-banged a floppy drive using a teensy4.0 and managed to write a full driver for it. My project code is hosted here on github in case you'd like to learn more. Continue reading for an extremely detailed overview
How do Floppy Disks Work Wiring Guide Sending Commands Synchronization Barrier Sector Metadata Track Metadata Further Reading
This website has a good overview and some nice pictures. Fundamentally, your floppy houses a magnetized disk that spins at about 300rpm. For 3.5" media, that disk contains 80 tracks. Each track has 18 sectors. Each sector has 512 bytes of user-space data (and some more bytes used for metadata). Most "modern" floppies are double-sided, so you can multiply all that by 2 in order to find the total amount of usable space per disk. 1,474,560 bytes in all.
joshcole.dev - a million projects
Two Stop Bits