Before Steve Jobs shut down the Advanced Technology Group (ATG) at Apple (in the late 1990's?), some coworkers reported having had a mini-tour of ATG and were blown away by a display they saw that "looked like paper!". If my memory is correct it was a 200 DPI LCD panel. No doubt that kind of DPI back in the 90's looked like paper. ;-)
I would love to see in person what over two decades has produced.
I don’t remember exactly when you joined up, or what the information flow would have looked like to the graphics group, but the OS team was certainly aware in the mid 90’s that high DPI displays were on the horizon.
I think it actually took much longer for them to become mainstream than Apple was expecting back then. Pre-NeXT takeover, this was one of the big impetuses behind moving to QuickDraw GX.
I was on the Quickdraw GX team just before it was blown up. But I think it was when I was on the ColorSync team that a few engineers popped over to ATG.
Considering the IBM "Big Bertha" LCD was an obtainable product in 2001, it doesn't seem too far-fetched that high resolution LCDs existed in some R&D labs years earlier.
It's not quite a 4K monitor, but I'll tell you it was pretty amazing to those of us who saw it demonstrated back then. This was a qualitatively different thing than we were familiar with. And, as I recall, it took 2 or 4 DVI inputs to drive it from typical graphics cards of the era. A single display output could not drive these kinds of pixel counts.
IBM had a CRT version of this before then. It worked the same by splitting the display into four quadrants. A Windows desktop only showed on one quadrant and you needed special software to use the whole display. The one we had at work was monochrome grayscale so it lacked the issues of dealing with a fine shadow mask.
LCD panels in that era were still being hand buffed and the defect rate would be high when attempting higher resolutions.
They started that project as Roentgen as I recall, and while they did exist there were eye-watering of expensive.
Around the time Apple started delivering HiDPI displays there was still a bit of scrambling by everyone to get software to play nice on OSX and Windows. Always fun when a game doesn’t realize you’re on a 270 DPI screen and makes the main menu so small you can barely read it to change the settings.
I would love to see in person what over two decades has produced.