CHS - Cylinder Head Sector GO FAR Wikipedia % for more information. Cylinder-head-sector (CHS) is an early method for giving addresses to each physical block of data on a disk drive.
Core Memory - Magnetic Core Memory GO FAR Wikipedia % for more information. Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975. Such memory is often just called core memory, or, informally, core.