IBM 5150
The 1981 IBM Personal Computer, an 8088 at 4.77MHz. Booted from a 360K floppy in its Tandon drive, onto an IBM 5151 monochrome monitor through a Hercules GB101 card, at 720x348.
Hercules - 720x348, and the Task Manager reads 3% with six programs
open.
Toshiba T1100 Plus
A 1986 laptop with an 8086 at 7.16MHz and a blue LCD, running the CGA driver at 640x200. The 360K images were written onto 720K floppies to get them in.
In VGA
os8088 at 640x480 in mode 12h on a CRT -- the mode every other screenshot on this site is taken in.
Run it yourself
The download page has the 360K images that were written to floppies for these machines. You need an 8086 or 8088, 128K of RAM, one floppy drive, a VGA, Hercules or CGA card, and a Microsoft serial mouse on COM1 -- the mouse is not optional, because every menu is press-drag-release.