Editing MultiFinder (section)

===MultiFinder===
{{see also|Mac OS memory management}}
MultiFinder, known before its release as "Juggler",<ref>{{cite magazine
| url = https://archive.org/stream/MacWorld_8709_September_1987#page/n13/mode/2up
| title = Mac Bulletin
| magazine = MacWorld
| date = September 1987
}}</ref> was introduced on August 11, 1987.<ref name="Mac GUI :: MultiFinder Announced"/> It is simply a way for windows from different applications to coexist by using a cooperative application layering model. Its initial release is able to handle only two concurrent applications, one of which runs in the background;<ref name="The new seekers">{{cite magazine| magazine=[[PC Magazine]] | title=The new seekers: Hypertext comes of age|url={{Google books|KU7dCBpP7fsC|page=108-109|plainurl=yes}}|page=109|date=November 24, 1987 | access-date=March 8, 2019}}</ref> and later releases allow many more concurrent applications. When an application is activated, all of its windows are brought forward as a single layer. This approach is necessary for [[backward compatibility]] with many of the windowing [[data structure]]s that were already documented. MultiFinder also provides a way for applications to supply their memory requirements ahead of time, so that MultiFinder can allocate a chunk of RAM to each according to need. This scheme, while functional, has severe limitations which cause many problems for users. Virtual memory was only available to contemporary Macs with a PMMU chip (Mac II-class machines required) and an extension named Virtual from [[Connectix]].<ref name="Orchestrating applications" /> Apple eventually provided virtual memory with the introduction of System 7.<ref>{{Cite book|title=Inside Macintosh: Memory|publisher=Addison-Wesley Publishing Company|year=1992|isbn=0-201-63240-3|location=Reading, Massachusetts|pages=3–5}}</ref>

Later in 1987, System 6 engineer Erich Ringewald's desire to solve these architectural problems altogether would bring him to defiantly cofound and lead the [[Taligent#Pink|Pink]] project as the intended future of a new MacOS,<ref name="Apple's First Stab">{{cite web | first=Tom | last=Hormby | date=April 27, 2014 | work=Low End Mac | title=Pink: Apple's First Stab at a Modern Operating System | url=http://lowendmac.com/2014/pink-apples-first-stab-at-a-modern-operating-system/ | access-date=February 1, 2019}}</ref> and then become chief software architect at [[Be Inc.]] to design [[BeOS]] in 1990.<ref name="Be Newsletter, Vol 3">{{cite magazine | magazine=Be Newsletter | title=Be Newsletter | volume=3 | issue=8 | date=March 25, 1998 | url=https://www.haiku-os.org/legacy-docs/benewsletter/Issue3-12.html | access-date=February 1, 2019}}</ref>

With the release of [[System 7 (Macintosh)|System 7]], the MultiFinder extension was integrated with the operating system, and it remained so in [[Mac OS 8]] and [[Mac OS 9]]. However, the integration into the OS does nothing to fix MultiFinder's inherent idiosyncrasies and disadvantages.<ref name="Orchestrating applications"/> These problems were not overcome in the mainstream Macintosh operating system until the MultiFinder model was abandoned with the move to a modern [[preemptive multitasking]] [[Unix]]-based OS in [[Mac OS X]]. Two utilities, CPU Doubler and Peek-A-Boo, did implement a form of priority based [[Scheduling (computing)|task scheduling]] in the classic Mac OS, though they were unable to solve its other issues, like the lack of [[protected memory]].<ref>[https://tidbits.com/2000/05/15/inspecting-gadget/ Inspecting Gadget - TidBITS]</ref><ref>[https://www.youtube.com/watch?v=DkNuO2KXv-8 How I Hacked a 90's Mac Kernel: CPU Doubler, a QL-like Task Scheduler/Task Manager - YouTube]</ref>