Drive sizes, doh!

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Luke M
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Drive sizes, doh!

Post by Luke M » Sun Aug 01, 2010 4:09 pm

I woke up from a nap today with a startling revelation. I will share it with you, free of charge.

The width of a 5.25" drive is 5.75".
The width of a 3.5" drive is 4".

The "drive size" refers to the width of FLOPPY DISKS - not drives!

2.5" drives are 2.75" wide. What does the 2.5" refer to? Good question, because to my knowledge 2.5" floppy disks never existed (2.0" disks did, see: http://en.wikipedia.org/wiki/Video_Floppy ). Perhaps the original 2.5" drives really were 2.5", but standardization resulted in a different size, while the 2.5" name stuck?

faugusztin
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Post by faugusztin » Sun Aug 01, 2010 4:30 pm

It was the size of the magnetic disk inside the floppy. You know, that black thing inside the plastic :)
http://scienceblogs.com/startswithabang ... y_disk.jpg

Luke M
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Location: here

Post by Luke M » Sun Aug 01, 2010 5:17 pm

3.5" floppies are actually 90mm (3.54") wide. The disk itself is 85.8mm (3.38").

andyb
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Post by andyb » Mon Aug 02, 2010 2:21 pm

The inch-based nickname of all these form factors usually do not indicate any actual product dimension (which are specified in millimeters for more recent form factors), but just roughly indicate a size relative to disk diameters, in the interest of historic continuity.

http://en.wikipedia.org/wiki/Hard_disk_drive


Andy

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