====== IBM 51xx PC Family Computers ======

  * [[http://minuszerodegrees.net/|Reference Manuals and Documentation]] [(https://web.archive.org/web/20190507124500/http://minuszerodegrees.net/index.htm)]
  * {{http://minuszerodegrees.net/oa/OA%20-%20IBM%20Color%20Graphics%20Monitor%20Adapter%20(CGA).pdf|IBM Color Graphics Monitor Adapter (CGA)}} [(https://web.archive.org/web/20181215121857/http://www.minuszerodegrees.net/oa/OA%20-%20IBM%20Color%20Graphics%20Monitor%20Adapter%20(CGA).pdf )] -- hardwrae reference