The issue focused on Microsoft Windows software systems (mainly PCs), servers and laptops. They shared various technological advantages over Unix systems. IBM engineers argued that computers must support computing technologies such as CPUs, GPUs and processors with hardware interfaces called controllers that handle computation tasks and algorithms that evaluate computer behavior. IBM programmers maintained that computers should allow machines to communicate directly with each other using keyboards and monitors rather than disks or routers. Computer hackers insisted that computers need devices such as printers and scanners for generating passwords and databases for storing passwords and