Here’s an example: What is Love on eight floppy drives - YouTube
Now some questions:
Why did these drives make so much noise? In the video it seems like the head movement causes the noise but the head moving mechanism is not much different from those on CD drives and these aren’t noisy at all. Is it because of the friction with the floppy disk?
Also how can you play the different notes? Are they related with how fast the heads move?
Floppy drives, especially those old 5.25" ones, were very noisy. Hard drives, too. Then there were the printers. And he has a very good microphone.
Floppy drives (as well as older hard drives) used to use these big clunky stepper motors to move the head from one track to the next. Stepper motors move in steps, going ka-chunk ka-chunk at each step, which sounds more like a brrrzzzzzzttttttt if it goes fast enough. By controlling the track to track seeks you can generate specific tones.
In the push to miniaturize things, modern drives use electromagnetic coils instead of stepper motors. They are a lot quieter.
Kids! Try this at home!
The real reason is that stepper motors are limited to discrete steps; if your platter has millions of tracks, you need a stepper motor with the precision to place the heads at each track (actual stepper drives, in the 10s of MB range, had maybe a few hundred tracks). Another problem is that stepper motor drives were prone to wear resulting in the heads coming out of alignment; it was often advised to reformat the drive once a year or so (as it says in an old book on computers I have). By contrast, a voice coil actuator drive can place its heads in any position, limited only by the accuracy of the DAC driving it (e.g. 24 bit DAC = 16.7 million “steps”). More on the differences here (note that modern drives don’t use one side of a platter for servo data, which is embedded with the data).
Floppy drives, hard drives, vinyl record players, and some LaserDiscs are all CAV or constant angular velocity meaning the disk always spins at the same RPM. This makes for a much simpler disk motor control (its speed remains constant) but it wastes space because the further out you move on the disk the faster it will be spinning, ergo the less data per linear unit is stored. In digital media the data is essentially in a series of concentric circles across the disk’s surface (not so for vinyl & LaserDiscs which are analog).
Audio CDs, CD-ROMs, DVDs, Blu-rays and also some LaserDiscs are CLV or constant linear velocity meaning the disc speed changes with the read/write head position (faster at the center then slower as it moves toward the edge). This makes the most efficient use of data storage in that the data ‘density’ is the same from start to finish, but the motor controlling the disc rotation has to constantly sync the speed based on the head’s position. Here the digital data is in one long, continuous spiral.
Anyway that’s why CAV drives makes the noises they do, especially old ones like floppy drives (and old MFM hard drives). The read/write head mechanism moves in discrete (and noisy) ‘steps’. It’s also why CLV (i.e. optical) drives make the noises they do (the sound of the disc itself speeding up and slowing down).
Yep, that’s what I meant by miniaturization. Good explanation, btw.
Reading back over what I wrote now I see that the bit about it being quieter might be misinterpreted as a reason for the switch. I intended it as a consequence, not a reason.
Which drives recommended a reformat? I don’t recall ever coming across that in older (mostly VAX) drives that I dealt with.
Modern hard drives are designed so that they can store more data on the outer tracks; this can be seen on hard drive speed tests, where the throughput increases towards the outer tracks due to more bits read/written per revolution (more than doubling in this example, the variations seen are just “noise”; note that hard drives start storing data on the outer tacks, which is one reason why a “full” drive seems slower). Of course, this requires complex control since the bit rate changes with head position (e.g. on the outer tracks the drive must reduce the width of pulses when writing so the magnetized areas stay the same size), but with modern chip technology and digital signal processing it is pretty easy to do (modern drives only have a few chips compared to older drives that didn’t use this and or/stepper motor drives).