UNIX

The history of Unix dates back to the mid-1960s, when the Massachusetts Institute of Technology, AT&T Bell Labs, and General Electric were jointly developing an experimental time-sharing operating system called Multics for the GE-645 mainframe. Multics introduced many innovations, but also had many problems. Bell Labs, frustrated by the size and complexity of Multics but not its aims, slowly pulled out of the project. Their last researchers to leave Multics – among them Ken Thompson, Dennis Ritchie, Doug McIlroy, and Joe Ossanna – decided to redo the work, but on a much smaller scale.

In 1997, Apple sought a new foundation for its Macintosh operating system and chose NeXTSTEP, an operating system developed by NeXT. The core operating system, which was based on BSD and the Mach kernel, was renamed Darwin after Apple acquired it. The deployment of Darwin in Mac OS X makes it, according to a statement made by an Apple employee at a USENIX conference, the most widely used Unix-based system in the desktop computer market.

NAS

Network-Attached Atorage (NAS)

Afile-level (as opposed to block-level storage) computer data storage server connected to a computer network providing data access to a heterogeneous group of clients. The term "NAS" can refer to both the technology and systems involved, or a specialized device built for such functionality (as unlike tangentially related technologies such as local area networks, a NAS device is often a singular unit).

ACL

Access Control List

In computer security, an access-control list (ACL) is a list of permissions associated with a system resource (object). An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on given objects. Each entry in a typical ACL specifies a subject and an operation. For instance, if a file object has an ACL that contains (Alice: read,write; Bob: read), this would give Alice permission to read and write the file and give Bob permission only to read it.

POSIX 1003.1e/1003.2c working group made an effort to standardize ACLs, resulting in what is now known as "POSIX.1e ACL" or simply "POSIX ACL". The POSIX.1e/POSIX.2c drafts were withdrawn in 1997 due to participants losing interest for funding the project and turning to more powerful alternatives such as NFSv4 ACL. As of December 2019, no live sources of the draft could be found on the Internet, but it can still be found in the Internet Archive.

Most of the Unix and Unix-like operating systems (e.g. Linux since 2.5.46 or November 2002, FreeBSD, or Solaris) support POSIX.1e ACLs (not necessarily draft 17). ACLs are usually stored in the extended attributes of a file on these systems.

Sidecar

Use an iPad as a second display for a Mac

With Sidecar, you can use your iPad as a display that extends or mirrors your Mac desktop.

Get ready

• Before continuing, make sure that your Mac and iPad meet the Sidecar system requirements, including that each is signed with the same Apple ID.

• You can use Sidecar wirelessly, but to keep your iPad charged during use, connect it directly to your Mac with the USB charge cable that came with your iPad.

Universal Control

Universal Control: Use a single keyboard and mouse between Mac and iPad

Use the keyboard, mouse, or trackpad of your Mac to control up to two other nearby Mac or iPad devices, and work seamlessly between them.

When using Universal Control, each device shows its own screen and apps, but you can use a single keyboard, mouse, or trackpad to move the pointer, type, and even copy content between them.

T2 Chip and Monterey Secure Erase

macOS Monterey includes Erase All Content and Settings, a way to quickly and securely erase all of your settings, data, and apps, while maintaining the operating system currently installed. If your Mac includes this feature when using macOS Monterey, use it instead of other utilities to erase your Mac.

On a Mac with Apple silicon or an Intel-based Mac with the Apple T2 Security Chip, use Erase Assistant to reset your Mac to factory settings before you trade it in or sell it. You can also use Erase Assistant to erase your Mac before reinstalling macOS. Erase Assistant removes your content and settings, and any apps that you installed.

Mac computers that have the Apple T2 Security Chip integrate security into both software and hardware to provide encrypted-storage capabilities. Data on the built-in, solid-state drive (SSD) is encrypted using a hardware-accelerated AES engine built into the T2 chip. This encryption is performed with 256-bit keys tied to a unique identifier within the T2 chip. 

About encrypted storage on your new Mac

The advanced encryption technology integrated into the T2 chip provides line-speed encryption, but it also means that if the portion of the T2 chip containing your encryption keys becomes damaged, you might need to restore the content of your drive from a backup. This content includes system files, apps, accounts, preferences, music, photos, movies, and documents.

Turn on FileVault

Though the SSD in computers that have the Apple T2 Security Chip is encrypted, you should turn on FileVault so that your Mac requires a password to decrypt your data.

Mac models with the Apple T2 Security Chip

These Mac computers have the Apple T2 Security Chip:

• iMac (Retina 5K, 27-inch, 2020)

• iMac Pro

• Mac Pro (2019)

• Mac Pro (Rack, 2019)

• Mac mini (2018)

• MacBook Air (Retina, 13-inch, 2020)

• MacBook Air (Retina, 13-inch, 2019)

• MacBook Air (Retina, 13-inch, 2018)

• MacBook Pro (13-inch, 2020, Two Thunderbolt 3 ports)

• MacBook Pro (13-inch, 2020, Four Thunderbolt 3 ports)

• MacBook Pro (16-inch, 2019)

• MacBook Pro (13-inch, 2019, Two Thunderbolt 3 ports)

• MacBook Pro (15-inch, 2019)

• MacBook Pro (13-inch, 2019, Four Thunderbolt 3 ports)

• MacBook Pro (15-inch, 2018)

• MacBook Pro (13-inch, 2018, Four Thunderbolt 3 ports)

You can also use System Information to learn whether your Mac has this chip:

1. Press and hold the Option key while choosing Apple menu  > System Information.

2. In the sidebar, select either Controller or iBridge, depending on the version of macOS in use.

3. If you see "Apple T2 chip" on the right, your Mac has the Apple T2 Security Chip.