The concept of extensions was not present in the original Macintosh system software, but the system nevertheless had a private patching mechanism that developers soon learned to take advantage of - the INIT loader. The phrase "system extension" later came to encompass faceless background applications as well.Įxtensions generally filled the same role as DOS's terminate and stay resident programs, or Unix's daemons, although by patching the underlying OS code, they had the capability to modify existing OS behaviour, the other two did not. Large amounts of important system services such as the TCP/IP network stacks (MacTCP and Open Transport) and USB and FireWire support were optional components implemented as extensions. Initially an Apple developer hack, extensions became the standard way to provide a modular operating system. They were run initially at start-up time, and operated by a variety of mechanisms, including trap patching and other code modifying techniques.
#MAC FILE EXTENSIONS MAC OS#
On the classic Mac OS (the original Apple Macintosh operating system), extensions were small pieces of code that extended the system's functionality. JSTOR ( February 2009) ( Learn how and when to remove this template message).Unsourced material may be challenged and removed.
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