disk vs. disc

<snip> Except for us storage geeks, I suspect disc is the common US spelling. IBM started us with Disk as in "The 650 RAMAC and 305 RAMAC both utilize the magnetic disk memory device ..." [650 RAMAC announcement, 1956] I have a 1963 Datamation article describing "Random Access Storage Devices" using the term disc throughout, including its characterization of the then several IBM "Disc [sic] Storage" devices. To its end, I think Datamation transformed disk into disc in its copy (not its ads) Early on there was some concern that the terms "Disk Pack" and "Disk File" were trademarks of IBM. Memorex used Disc as does Seagate. CDC used Disk. IBM brought us "Diskette" for the 8-inch FD media, Pioneers like Memorex and Potter called it a "Disc Cartridge", but it was probably Century Data that brought us to the "Floppy Disk" and Shugart that established it as the defacto standard in the language. ANSI and other standards groups called them Flexible Disk Cartridges. "Compact Disc" et al are trademarks and to use or make compatible media you have to be licensed and had to follow the logo standard. Someone from Sony/Philips will have to say why they chose Disc instead of Disk. It may be just that they had to make a choice of one or the other. Tom