Linus Torvalds use of assembly language. After the VIC-20 he purchased a Sinclair QL, which he modified extensively, especially its operating system. "Because it was so hard to get software for it in Finland, Linus wrote his own assembler and editor (in addition to Pac-Man graphics libraries)" for the QL, as well as a few games. He wrote a "Pac-Man" clone named "Cool Man". On January 5, 1991 he purchased an Intel 80386-based clone of IBM PC before receiving his MINIX copy, which in turn enabled him to begin work on Linux. The first prototypes of Linux were publicly released later that
Security-evaluated operating system in August, 1987. The Unisys OS 2200 operating system includes an implementation of the DoD Orange Book B1, Labeled security protection level specification. OS 2200 first obtained a successful B1 evaluation in September, 1989. Unisys maintained that evaluation until 1994 through the National Computer Security Center Rating Maintenance Phase (RAMP) of the Trusted Product Evaluation Program. Security-evaluated operating system In computing, security-evaluated operating systems have achieved certification from an external security-auditing organization, the most popular evaluations are Common Criteria (CC) and FIPS 140-2. Trusted Solaris 8 was a security-focused version of the Solaris Unix operating system. Aimed primarily at the