core n.
Main storage or RAM. Dates from the days of ferrite-core memory; now archaic as techspeak most places outside IBM, but also still used in the Unix community and by old-time hackers or those who would sound like them. Some derived idioms are quite current; `in core', for example, means `in memory' (as opposed to `on disk'), and both core dump and the `core image' or `core file' produced by one are terms in favor. Some varieties of Commonwealth hackish prefer store.