Idle DR-DOS
I continue to be amazed by Michal Necasek's ability to deeply care about things that literally nobody has even <i>thought</i> about for decades. Kudos!<p>Power management under DOS on early x86 laptops was downright primitive. There were no standards of <i>any</i> kind (I'd never even heard of the DR-DOS $IDLE$ device until now, but it doesn't seem like that gained any kind of traction at the time), not even BIOS-based abstractions. Just vendor-provided 'drivers' (in name only: it's not like DOS made any distinction between system and user code) that directly communicated with the hardware.<p>Unsurprisingly, that all broke down as soon as you did anything even remotely interesting. Run QEMM386? No power management for you! Have a certain PCMCIA card inserted? Ditto! And shipping any kind of updates took forever at that time (literally FedExing floppies...), so getting a working system was pretty much impossible.