> I assume the hard disks that came before worked more like the floppy and their controllers did more work too. You nailed it. The first hard disk interfaces f

> I assume the hard disks that came before worked more like the floppy and their controllers did more work too. You nailed it. The first hard disk interfaces for IBM PCs were basically identical to the floppy disk controller just faster/bigger. https://en.wikipedia.org/wiki/ST506/ST412 https://en.wikipedia.org/wiki/ST506/ST412 The ST506 interface between the controller and drive was derived from the Shugart Associates SA1000 interface,[5] which was in turn based upon the floppy disk drive interface,[6] thereby making disk controller design relatively easy But as they started wanting to make disk reads faster and faster, the drive part had to get smarter and smarter The ST412 disk drive, among other improvements, added buffered seek capability to the interface. In this mode, the controller can send STEP pulses to the drive as fast as it can receive them, without having to wait for the mechanism to settle. An onboard microprocessor in the drive then moves the mechanism to the desired track as fast as possible At that point the drive is starting to getting smart enough that you might as well integrate the whole controller on there. The original versions of IDE/ATA were basically just an extension of ISA, and the first "IDE cards" were just a bridge to the ISA slot they went in. You also had "hard cards" where the hard disk itself was integrated onto the ISA card... https://en.wikipedia.org/wiki/Hardcard https://en.wikipedia.org/wiki/Hardcard