OVL File
The OVL file extension refers to MS-DOS overlay files used in the pre-Windows era. They were used by 400kb systems to handle files larger that 400kb. They helped software developers overcome these existing memory limitations, because back then random-access memory was between 16K and 64K. That's why it was impossible to fit an entire program code into the available system memory.
OVerLay files represent a portion of the object code loaded on demand by an overlay manager from external memory into the destination region. It was a handy means of memory management allowing developers to build applications that were larger than the computer's main memory. OVL files were used by such programs as dBase database management system, WordStar word processor and others.
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