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# System 4

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![https://github.com/seanpm2001/WacOS/blob/master/Graphics/System-software/1/Apple_Macintosh_Desktop.png](https://github.com/seanpm2001/WacOS/blob/master/Graphics/System-software/1/Apple_Macintosh_Desktop.png)

( **Predecessor:** [System 3 (1986)](https://github.com/seanpm2001/WacOS/wiki/Apple-System-3/) | **Successor:** [System 5 (1987)](https://github.com/seanpm2001/WacOS/wiki/Apple-System-5/) )

Apple System 4 is the fourth major version of the then-to-be classic MacOS series of operating systems produced by Apple Inc.

System 4.0 was released with the Macintosh SE and System 4.1 first shipped with the Macintosh II—these new machines required additional support for the first expansion slots, the Apple Desktop Bus (ADB), internal hard drives and, on the Macintosh II, external color displays and the first Motorola 68020 processor.

**This article on classic Mac OS is a stub. You can help by expanding it.**

**This article is a modified copy of the Wikipedia article of the same subject. It needs to be rewritten to be more original.**

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## Sources

[Wikipedia - Classic Mac OS # System 1-4](https://en.wikipedia.org/wiki/Classic_Mac_OS#System_2)

Other sources are needed, and this article needs LOTS of improvement and original work to prevent it from being a copy and paste from Wikipedia.

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## Article info

**Written on:** `2021 Thursday September 23rd at 2:35 pm`

**Last revised on:** `2021 Thursday September 23rd at 2:35 pm`

**File format** `Markdown document (*.md *.mkd *.markdown)`

**Article version:** `1 (2021 Thursday September 23rd at 2:35 pm)`

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