And that standard PC's DMA controller was originally intended for use with the 8-bit 8080 (eighty-eighty, not eighty-eight) processor. It was slow and only supported 16 bit addresses. IBM added a latch that would store the high address bits, but they weren't incremented when the lower bits wrapped around. So buffers had to be allocated in a way that they didn't cross those boundaries, and the BIOS disk functions would return an error if your code didn't do this properly.
A marvelous machine. High resolution (if monochrome), Hercules-like graphics, for example.
But the kicker was that it actually had an MMU[1], built from discrete logic chips, in order to run SINIX (a Xenix 8086 derivate, but with added MMU support among other things) and enjoy full memory protection. I reverse engineered that MMU, it's quite fun. Paging wasn't possible though.
[1] Early on as a variant called "PC-X", but they apparently did away with the early board revisions, and all machines I've seen say "PC-D/PC-X" on the back, so they all have the MMU and can be both.
Nevertheless, due to their high cost for those times none of these 2 CPUs had seen much use before two years and a half later, when IBM launched the IBM PC/AT in August 1984.
Most programmers have encountered INS and OUTS for the first time while using PC/AT clones with 80286. Embedded computers with 80186 became common only some years later, when the price of 80186 dropped a lot.
However they have been launched only in 1984 and computers made with them have become available only some years after the PC/AT with 80286, most likely even later than the launch of 80386, so despite that they implemented all the 80186 extensions they do not count when discussing the timeline of the INS/OUTS introduction.