A disk pack or disk drive reserved only for system software, which includes the operating system, assemblers, compilers and other utility and control programs.
"systems disk." YourDictionary, n.d. Web. 17 August 2018. <http://www.yourdictionary.com/systems-disk>.
systems disk. (n.d.). Retrieved August 17th, 2018, from http://www.yourdictionary.com/systems-disk