64628f99_nical_Details_and_Instructions__Description
[Signal Name] DISK CHANGE [Description] 
This lets the host machine know that the floppy drive has been unloaded and reloaded, with a different or possiblity the same disk. There are several behaviors that have been chosen by the various manufacturers, meaning the signal itself is not cross-compatible 100%. The disk change signal on the 1-IBM is different than the 1-SW.
USB Floppy Disk Drive Converter/Emulator Technical Details and Instructions
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