This set of two DVD-ROM discs contains a 50-year archive of:Narrow Gauge and Short Line Gazette - every page from the first issue in 1975 through the end of 2014 (239 issues)- and complete collections of the GAZETTE's predecessors:FINELINES (57 issues)SLIM GAUGE NEWS (18 issues)A total of 25,220 pages with 1,828 plans and scale drawings. All issues are fully searchable by title, author, keywords and text entries. All pages are printable as PDF files.These DVD-ROM discs are for use in a computer DVD drive ONLY. They will not play on a stand-alone DVD player.System Requirements:WINDOWS:Microsoft Windows XP, Vista, Windows 7 or 8;2.33 GHZ or faster x86-compatible processor;1 GB RAM;DVD-ROM Drive;1152 x 864 minimum screen resolution;2 GB of hard drive space for basic install;14 GB of hard drive space for full install.MAC:Mac OS X v.10.6, v10.7 or v10.8;Intel Core Duo or faster processor;1 GB RAM;DVD-ROM drive;1152 x 864 minimum screen resolution (1280 x 720 recommended);2 GB of hard drive space for basic install. 14 GB of hard drive space for full install.