glen wrote:
Traditionally, at least for IBM style drives, the index hole is only during formatting.
Gen:I think you are mistaken. The index hole is used by the PC drive mechanism itself. If the mechanism does not see a pulse every so often then it shuts down the drive motor.
Don't believe me?Try this: cover the hole with an opaque post-it note or two and see how long the drive spins.
Try this: Open a formatted PC floppy disk and flip the media over and insert the disk upside down in the drive.
My theory: the index hole circuit is used to indicate the drive is spinning, otherwise it assumes the drive is empty or jammed.
Thankx, Ed