View Full Version : How does a computer with DOS in ROM work?

March 13th, 2017, 06:35 PM
I know a few computers back in the day had a dos in its ROM which was embedded into the Bios , mostly 8086 based machines but a few 386 or even 486, most of them were DOS palmtops like the hp lx series, and also the omnibook series which also had windows 3.1 with it in ROM as well. Also a few desktops had it as well. How did this work? was it like a virtual disk image in rom, that the bios booted? or was it like it was it ROM with no file system or disk image with just the binaries embedded in with the bios, and the bios had code to put everything in memory, which i believe which created a rom disk, which i think was just a virtual disk , possibly linking the files from ROM into the disk Im pretty sure the DOS and its applications where XIP or execute in place, which means it didn't need to load the programs or DOS into ram to work.