Can anyone tell what are the dimensions and/or volume for a 3.5-inch floppy disk?
I am doing a presentation and want to make a visual on how many floppy disks are required to save 200 GB (73662 floppy disks I believe).
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Sign up to join this communityCan anyone tell what are the dimensions and/or volume for a 3.5-inch floppy disk?
I am doing a presentation and want to make a visual on how many floppy disks are required to save 200 GB (73662 floppy disks I believe).
A standard 3.5" floppy disk (ANSI X3.137 or ANSI X3.171 size) is physically 90mm x 94mm x 3.3 mm, with a 85.80 mm diameter magnetic disk in the cartridge.
This is the same whether the media is DD, HD or ED inside - so 720k and 2.88M DOS formats are the same physical size.
I believe, but cannot find references to verify this, that the LS-240 media (240 MB disks) was the same physical dimensions as the ANSI standard floppy.
The ECMA-147 standard (and, I am told, the ANSI X3.137 standard too) defines the dimensions of a ‘3.5 inch’ floppy disk as 90 mm × 94 mm × 3.3 mm, which multiplies up to a volume of 27918 mm³ = 27.918 ml (though this is arguably imprecise as it includes the volume of all the notches that, strictly speaking, aren’t part of the floppy disk cassette).
Storing 200 GB of data on floppy disks in probably the most common high-density PC format (1440 KiB each) would require ⌈200 × 1000³ ÷ (1440 × 1024)⌉ = 135 634 floppy disks, so your figure appears to be about two times too small. But even that doesn’t take into account file system overhead; assuming each floppy contains a FAT12 file system with standard sector reservations (1 boot sector, 14 sectors for directory entries, 2 FATs of 9 sectors each) containing a single file, you end up with ⌈200 × 1000³ ÷ (2847 [sectors] × 512 [bytes per sector])⌉ = 137 206 disks. If it’s just for illustrative purposes the difference probably doesn’t matter too much, as it’s still roughly the same order of magnitude, but it would be a quite significant one if storing all that data was actually attempted.
Other stats for your 73,662 floppies:
They would weigh roughly 1326 kg. This is about the same as a Mini Cooper S car.
The labels on their backing paper would cover an area of almost 325 m² (assuming Memorex labels, which came on a 76 × 58 mm sheet): enough to cover the floor of the US White House's Oval Office 4¼ labels deep.
A roll of labels to label every one would be 4.27 km long (assuming 58 mm per label)
If packed in boxes of 10 like you got from Memorex, you'd need 7367 boxes, each 94 × 45 × 97 mm. This would cover a standard shipping skid/pallet (1.2 × 1 × 0.162 m) to a height of just over 2.7 m. This wouldn't fit inside a standard sea can / shipping container: they only have a headroom of 2.38 m.