... like in the PC AT, PC XT[1] or the Compaq DeskPro 386[2] that the article discusses didn't have those ports at all.
Those were instead on ISA expansion cards, just like the floppy controller that would often share a card with the UART controller for the serial interface.
IDE was just coming in (in the UK) in 1990. The acronym got updated to "AT Attachment" because "Integrated Drive Electronics" was generic, and it wasn't as if the older drives had no electronics on them. Much later when SATA showed up, the name evolved again as ATA became known as Parallel ATA to distinguish the two.
Before that, when you installed a hard disk you had to go into the BIOS to specify the geometry of the drive. 46 types were already defined, to match individual drives on the market. "Type 47" allowed -- required -- manually specifying the drive geometry in terms of cylinders, heads and sectors. So for a short while some traditional MFM or RLL drives would be informally classed as Type 47 because their geometry and capacity differed from earlier drives.
Yes, the earliest mainboards I know of with on-board I/O including ATA is around Socket 5, the first mainstream Pentium boards. Some slightly older Socket 4 boards (circa 1994) have on-board I/O, but they weren't as common.
My 486 and earlier systems have all I/O provided by ISA cards, other than the 5-pin DIN keyboard port which was standard since the original PC.
I remember my dad's Dell 486P/33 from 1991 had integrated IDE, but that was a fairly high-end machine at the time (the forerunner of their "Precision" workstation range).
Wow! Very impressive board, I had no idea. It's kinda cool how we can directly see some of the chips that would be on the SuperIO card but directly on the mainboard. Thanks for sharing.
White box systems didn't really acquire onboard I/O til the late 486/early 586 era, but it was pretty common on name-brand systems to integrate IDE/floppy/serial/parallel and usually video.
Before that, when you installed a hard disk you had to go into the BIOS to specify the geometry of the drive. 46 types were already defined, to match individual drives on the market. "Type 47" allowed -- required -- manually specifying the drive geometry in terms of cylinders, heads and sectors. So for a short while some traditional MFM or RLL drives would be informally classed as Type 47 because their geometry and capacity differed from earlier drives.