Like most local service airlines Southern flew only Douglas DC-3s for the first few years. In 1961 they began adding 22 40-passenger secondhand Martin 4-0-4s acquired from Eastern Air Lines, newer aircraft that were pressurised and had a rear ventral stairway. The last DC-3 was retired in 1967.
Community Q&A. An operating system (OS) is software that manages the interaction between hardware resources and the programs or applications you use on a computer. Most PCs have a version of the Windows operating system on them but Macintosh, Linux and UNIX are other popular operating systems.
MS-DOS (/ËÉmÉsËdÉs/ EM-es-DOSS; acronym for Microsoft Disk Operating System) is an operating system for x86 -based personal computers mostly developed by Microsoft.