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Protected memory was only added to Macintosh computers with the release of the Mac OS X operating system. According to Andy Hertzfeld, the Macintosh used for the introduction demo on January 24, 1984, was a prototype with 512k RAM, even though the first model offered for sale implemented just 128k of non-expandable memory. This prototype was ...
Though the memory had been quadrupled, it could not be upgraded. The large increase earned it the nickname Fat Mac. A 64 KB ROM chip boosts the effective memory to 576 KB, but this is offset by the display's 22 KB framebuffer, which is shared with the DMA video controller. This shared arrangement reduces CPU performance by up to 35%.
Some (or all) of the CPUs can share a common bus, each can also have a private bus (for private resources), or they may be isolated except for a common communications pathway. Likewise, the CPUs can share common RAM and/or have private RAM that the other processor(s) cannot access. The roles of master and slave can change from one CPU to another.
The 9500 is also the first computer from Apple to support 168-pin DIMM memory modules, and the 512 KB of on-board 128-bit-wide cache utilizes copy-back instead of write-through, offering faster speeds than prior Macintosh models, [3] as well as the ability to install single modules (although matched pairs are recommended for best performance [5]).
The Macintosh Plus was the last classic Mac to have an RJ11 port on the front of the unit for the keyboard, as well as the DE-9 connector for the mouse; models released after the Macintosh Plus would use ADB ports. The Mac Plus was the first Apple computer to utilize user-upgradable SIMM memory modules instead of single DIP DRAM chips. Four ...
In computing, a keyboard controller is a device that interfaces a keyboard to a computer. Its main function is to inform the computer when a key is pressed or released. When data from the keyboard arrives, the controller raises an interrupt (a keyboard interrupt ) to allow the CPU to handle the input.
This is also the first Power Macintosh with the "New World" architecture which contained a small (approximately 1 MB) boot ROM. When booting the Mac OS, the Mac OS Toolbox and any other ROM patches installed are loaded into RAM (the former Beige G3 however was the first Mac with this ROM-in-RAM capability).
Its CPU cores are the first to be used in a Mac processor designed by Apple and the first to use the ARM instruction set architecture. It has 8 CPU cores (4 performance and 4 efficiency), up to 8 GPU cores, and a 16-core Neural Engine, as well as LPDDR4X memory with a bandwidth of 68 GB/s.