An operating system can retain its memory between reboots using only RAM, as long as the reboots are not "cold" reboots (that is, machine powered off and then b

An operating system can retain its memory between reboots using only RAM, as long as the reboots are not "cold" reboots (that is, machine powered off and then back on, or reset through hardware instead of software). It of course depends on hardware support, but it can be done even today on select platforms.