If the information is stored at some value of bits per cm… There’s less bitrate (bits per revolution) in the middle of the record vs the outer edges.
If the information is stored at some value of bits per cm… There’s less bitrate (bits per revolution) in the middle of the record vs the outer edges.
Which is why Macintosh floppy disk drives were changing their rotational speed depending on which cylinders were being accessed, so that the information density would in fact be uniform.
Which is why a Mac floppy could hold 400/800k compared to a DOS floppy’s 360/720k.
So do CDs. 💿 If you have a player with a see-through lid, you can see the disc rotate around 2.5 times slower on the last track of a near-74/80-minute disc as opposed to the first. This might not apply with modern (2000+) and/or portable ones with cache (ESP) − MP3 support is a good clue it has the advanced electronics for that. And yes, CDs’ track starts at the center to enable shorter, smaller disks.
Players regulate the motor speed based on the data clock (and burners too: there is a pre-recorded “timing” signal even on blank CD-Rs) so technically, a constant-angular-velocity CD could be pressed and played on most players, just with no real benefits.
Huh. Cool facts.
That’s a lot of complexity added for 80kb. Curious if there was much software that just wouldn’t have fit on a single floppy otherwise.
It’s an 11% increase, that’s huge. Floppies weren’t just used to store programs, also to store files.
Some of the first real home/office PCs had only one floppy drive and 640kb of RAM. Fancier machines had a second floppy. If you were a millionaire, you could get a HDD with upwards of 30Mb storage.