[retrogeek]

Sort of? For slotted classic Apple II's - the original ][, ][+ and //e - there was always the ubiquitous "Disk II" controller, which came in a couple of variants (2x20-pin connectors or single DB-19). These were made in enormous quantities back in the day and are fairly common and mostly affordable, but they will also only operate one or two of the original "dumb" 5.25" floppy drives.

The later, more advanced slot-based controllers like the "Liron" and UDC cards that can operate 3.5" floppies as well as certain large-capacity "SmartPort" HDD's (with up to a whopping 32M per device!) are MUCH MUCH harder to find and have price tags to match, easily exceeding the US$150 mark when they do appear. The "Liron" card also ONLY operates one or two of the "smart" UniDisk 3.5" floppy drives or SmartPort HDDs - no 5.25" drive capability - and those smart drives tend to command some pretty hefty prices as well. The VTech UDC, which can operate the cheaper "dumb" 3.5" floppy drives and legacy 5.25" drives and is the closest vintage product to the Yellowstone, borders on unobtainium. My UDC cost me well over US$200.

The Yellowstone will happily operate ANY of these device types, including 5.25" and 3.5" floppies - in both "dumb" and "smart" versions - as well as the compatible SmartPort HDDs. It will also handle multiple drives as long as they're attached in certain specific orders and combinations, with as many as five different drives being able to run from a single Yellowstone. So the Yellowstone does a pretty good job of providing a modern, robust, available, and flexible solution to attaching drives to a slotted classic 8-bit Apple. For its price it easily competes with or beats the genuine vintage options.

Anecdotally, I expect that the controller situation is part of the reason that the Apple //c is in such high demand. The //c is more or less 100% compatible with a //e and its disk controller port includes pretty much the same capabilities as both a "Disk II" controller AND a "Liron" interface card built into it, out-of-the-box.