"(The spelling disk and disc are used interchangeably except where trademarks preclude one usage, e.g. the Compact Disc logo. The choice of a particular form is

"(The spelling disk and disc are used interchangeably except where trademarks preclude one usage, e.g. the Compact Disc logo. The choice of a particular form is frequently historical, as in IBM's usage of the disk form beginning in 1956 with the "IBM 350 disk storage unit").": https://en.m.wikipedia.org/wiki/Disk_storage https://en.m.wikipedia.org/wiki/Disk_storage