PC/MS DOS
In the DOS era overlays were popular because the operating system and many of the computer systems it ran on lacked virtual memory and had very little RAM by current standards — the original PC had between 16K and 64K depending on configuration. "Several DOS linkers in the 1980s supported in a form nearly identical to that used 25 years earlier on mainframe computers." Binary files containing memory overlays had a defacto standard extension, .OVL. This file type was used among others by WordStar and dBase. The GFA BASIC compiler was able to produce .OVL files.
Read more about this topic: Overlay (programming)
Famous quotes containing the word dos:
“Why wont they let a year die without bringing in a new one on the instant, cant they use birth control on time? I want an interregnum. The stupid years patter on with unrelenting feet, never stopping—rising to little monotonous peaks in our imaginations at festivals like New Year’s and Easter and Christmas—But, goodness, why need they do it?”
—John Dos Passos (1896–1970)