Dec 21, 2020 • Filed to: Solve Mac Problems • Proven solutions
A Universal Serial Bus or USB Drive, also known as a flash drive is a portable data storage device that includes a memory which includes a USB interface. It is typically removable and much smaller than an optical disc. Any sort of data can be stored in this device. The drives are available in various sizes and as of to date, the 2TB(Tera-Byte) flash drives in terms of storage capacity are the largest ones available in the market.
Today, these drives are one of the most consumed used devices in the world. Thanks to their portable nature, affordability, and compatibility, USB drives are being used to send and receive endless information across a surplus of networks and platforms all around the globe. This small tool has opened the world to a stream of limitless options with respect to storing, transferring, copying data, and much more. One of them includes Booting the Mac from such a device.
Part 1. Reasons for Mac Boot from USB
Booting the Mac from USB in a way gives the power back to the user. The likeliest of the reason for choosing the boot from the USB method is that your Mac won't start which denies the user access to the computer. Using an external source like the USB drive helps the user get around the problem. It provides the user access to the contents of the internal drive, assuming the data is safe and not corrupted. It also helps to repair the Mac disk with Disk Utility and other tools. Here are the top reasons why the user should choose to Boot Mac from USB:
No internal modem. External Apple USB modem was offered for US$49. Gigabit Ethernet, AirPort Extreme (802.11g) and Bluetooth 2.0+EDR standard (entry-level iMac 'Core 2 Duo' 1.83 17-Inch (IG) model lacks Bluetooth). Also see: What are the differences between the iMac Core 2 Duo models? I was given a late 2006 iMac with the hard drives erased and no OS loaded. The iMac boots to flashing folder. I purchased a Mac OS Tiger Install DVD but it is not bootable. I also have a Mac OS Leopard Drop-in DVD that will boot to the installation menu but will not install because 10.4 is not found on the HD. There’s more variety than ever before in the iMac line. The entry-level 1.83 GHz model uses Intel GMA 950 graphics, carried over from the education iMac introduced in July 2006. This model comes with a Combo drive, 512 MB of RAM (2 GB maximum), a 160 GB hard drive, two FireWire 400 ports, and Apple’s USB keyboard and Mighty Mouse. Reasons for Mac Boot from USB. Booting the Mac from USB in a way gives the power back to the.
- Allows the user to install a different version of macOS.
- It allows the user to test a new version before you make the decision to upgrade.
- Allows risk-free testing of the Beta version.
- Faster and efficient.
- By installing older versions through USB, it permits certain Apps to run which are not compatible with the latest macOS.
Part 2. Preparations for Booting Mac from USB
To ensure a risk-free procedure certain measure should be taken:
- The user should buy a name-brand flash drive.
- The USB should contain 16-32GB of free space.
- The user should scan the flash drive with some reputable Anti-Virus software.
- The user should check to see what size of ports they have on the Mac. A 12' Mac only contains a single C-Type port.
- Make sure to purchase the C port flash drive to avoid any inconvenience.
- It is advised that the user should go with a USB 3.0 supported drive, with a size of 16GB to ensure a swift transfer of data.
- The USB drive should be formatted with a supported GUID partition.
- It should contain an OS X installer or a usable operating system to work with.
Part 3. How to Create Bootable USB on Mac
There are a few general guidelines that can help get your machine started which are mentioned above, regardless of the OS the user prefers. Here are the methods to create a bootable USB drive on Mac.
Creating a Bootable USB Using Terminal
The terminal is the default gateway to the command line on a Mac. It is just like the Command Prompt feature works for MS Windows. The Terminal feature ensures a hassle-free experience for the Mac user without the conventional pointing and clicking, the user just has to type the commands and the computer does the rest. The user can find Terminal in the Applications > Utility folder or it can be checked in the finder utility.
Related: Further, read and know more complete details on Mac Terminal.
Using the Terminal feature is the most simple way to create the bootable USB drive. The user just needs to follow one easy step which is renaming the MyVolume portion of the command with the name of the drive. The name of the drive can be changed using the Disk Utility of Mac. Here are the steps required after opening the Terminal feature to create a bootable USB drive.
- Copy and paste the command which is suited for the version of the operating system into the Terminal window.
- The command for MacOS Mojave is as follows:
sudo/Applications/InstallmacOSMojave.app/Contents/Resources/createinstallmedia --volume/Volumes/MyVolume - Press the Return key.
- Enter the password.
- Confirm to erase the USB drive by typing Y followed by the Return key.
- The terminal will erase all the data inside the drive and create the bootable USB drive.
If there is a need to install a different version of the operating system then the user just has to replace the above-underlined command with their desired version of OS. For example, if the user wants to install Mac OS Sierra instead of Mojave then they would have to replace 'Mojave.app' with 'Sierra.app' inside the command line.
Part 4. How to Boot Mac from USB Media
After creating a bootable USB drive, the user simply needs to plug the created drive into the open port on the Mac. Here are the steps to boot Mac from the USB flash drive:
- Power on the system.
- Press and hold the Option (Alt) key on the keyboard when the computer starts.
- Select the USB drive as a startup disk when the option appears.
- The system will start the boot process off the USB drive.
- Install the operating system from the macOS utilities.
- Data can be restored by using the Time-Machine backup option.
Video Tutorial on How to Boot Mac into Recovery Mode
Part 5. How to Recover Data from Unbootable Mac
The Mac becomes unbootable when the BIOS which is a firmware that is used to perform hardware initialization during the booting process fails to recognize the startup process. It usually happens when there is a failed system update, system crash, damaged MBR, or when the drive becomes corrupt.
Recoverit Mac Data Recovery software is the most efficient option to recover all the lost data when Mac becomes unbootable. Developed by Wondershare, Recoverit is one of the most preferred recovery tools in the world. The tool provides an instant preview of what is recovered after a detailed scan. It allows us to connect almost every type of portable device and recover data from them. Data can be restored by performing the recovery and repair process. The process involves the installation of the Recoverit software that offers users the chance to get back the important data that they had lost.
Step 1. Create a Bootable Media
To recover data from an unbootable Mac, you need to create a bootable media first.
- Installation: Please Install Recoverit by clicking on the icon.
- Select an option: For your crashed Mac, please choose the 'Computer Crash Recovery' option.
- Initiate Recovery Process: Click on 'Start' for the recovery process to launch.
- Create Bootable Drive: Select the 'Create USB bootable drive' option and click on 'Create'.
- A pop-up dialogue will appear that will prompt the user to format the USB drive.
- Format the Drive: Click on 'Format' Now.
- Recoverit will show you the process of formatting the USB drive and creating a bootable drive.
- After a while, the bootable drive will be built up. And please follow the guides which Recoverit shows you.
Step 2. Recover Data from Crashed Mac
Here are the following steps required to recover data from an unbootable computer.
1. Select the Location
When you launch Recoverit, you can select a location to scan. In this case, we will be performing data recovery on Mac's internal hard drive (Macintosh HD) instead of any other connected source.
2. Scan the Location
As soon as you would click on the 'Start' button, Recoverit will take the needed steps for data extraction. If you want positive results, then try not to close the application in between.
3. Preview and Recover
When the data recovery process is completed, the application will display the results on the interface. You can go to any category of your choice from here and preview the retrieved content. Make the needed selection and click on the 'Recover' button to save your files to a secure location.
All hope gets lost when the computer becomes unbootable and the data gets deleted. Recoverit recovery software is the most convenient program when it comes to retrieving lost data from the computer.
Installing the macOS from a USB flash drive gives the user an instant solution when the Mac installer due to some reason refused to work. The method to create a bootable drive is easier than it sounds. Now, you know what to do whenever you want to upgrade your macOS from a bootable external source by following different methods to ensure a safe and hassle-free process. If you lose valuable data when the Mac becomes unbootable then you can easily recover the lost files by using the Recoverit recovery software. Recoverit guarantees data recovery in no time.
What's Wrong with Mac
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Rosetta wasn't the ideal solution during Apple's hardware transition in 2006, but it was a decent temporary fix to run PowerPC-based apps on Macs with Intel CPUs. Now, Rosetta 2 arrives in macOS Big Sur promising faster performance and better support on Apple Silicon.
● Brings current Intel-based Mac apps to Apple Silicon
● Faster than Rosetta
● Translates at install, not during execution
● Translates on-the-fly as needed
● Available in macOS Big Sur
● Supports Universal 2 file format
● Faster than Rosetta
● Translates at install, not during execution
● Translates on-the-fly as needed
● Available in macOS Big Sur
● Supports Universal 2 file format
In significant hardware transitions, one of the biggest challenges is app support. Apps developed to run on a specific processor won't run on another without recoding and recompiling. Apple solves this problem with Rosetta 2 in macOS Big Sur.
Tim Cook explains Apple's transition from Intel-based Macs
This is a behind-the-scenes feature in macOS Big Sur as part of Apple's shift away from Intel-based Mac designs. It's used to translate Intel-based Mac apps so they can run on Apple Silicon Macs without having to modify the source code.
More specifically, it translates x86_64 processor instructions (aka 64-bit Intel) for ARM-based Apple Silicon, which debuted on Macs with the M1 chip. It's not meant to substitute native apps but to give developers time to create a 'universal binary' for apps already offered on Mac.
Rosetta 2 works with Intel-based apps distributed through the Mac App Store and desktop applications downloaded and installed from external sources.
The big difference with Rosetta 2 compared to the original version is that it automatically translates non-native apps when they're installed, not during runtime. This increases the app's overall performance because there is no additional processing overhead. However, it does translate code on the fly as needed, like just-in-time (JIT) JavaScript compilers for web browsers.
During the PowerPC transition, when the user launched an app, the operating system kernel (core) looked to see if the app had a native binary. If not, the kernel executed the binary using Rosetta. Both Rosetta and the app ran in the same processing thread, allowing the former to quickly translate a block of application code and execute that specific block. This method is referred to as just-in-time (JIT) compilation.
Apple's documentation states that when Rosetta encountered a call to a routine that it had not yet translated, it translated the needed routine and continued the execution. This process ensured 'smooth and continual transitioning between translation and execution.' Rosetta also optimized the translated code to provide a near-native experience on non-native hardware.
If the developer chose to compile an app using the Universal binary format, users had the option to run the non-native executable using Rosetta. This allowed them to use older PowerPC-based plugins that did not natively support Intel's CPU architecture.
Rosetta 2 in macOS Big Sur supports 'the most complex Pro apps and their plugins.'
Apple Silicon for Mac will be based on the arm64 architecture
Apple made a significant hardware transition in 2006 when it switched from PowerPC processors to Intel. This is notable because Apple didn't merely swap out CPUs and move on. PowerPC and Intel use two different processor designs, carrying out processing instructions differently.
At the time, that meant Mac owners couldn't run software designed for a PowerPC machine natively on an Intel-based PC (aka x86) without real-time translation or rewriting the code to 'speak' a different Intel-based language. Both methods had their advantages and disadvantages.
Apple currently faces the same issue with its transition away from Intel processors to those based on ARM's CPU architecture. Unlike the first transition, where Apple redesigned Macs around Intel's chips, Apple now creates in-house processors using a base design it licenses from Arm Holdings. The latter company doesn't fabricate chips – it designs the core technology and licenses it out so CPU makers can include unique features.
Apple uses ARM's designs in all in-house processors installed on the iPhone, iPad, iPod Touch, Apple TV, Apple Watch, and the HomePod. Most of those are mobile devices, and ARM hasn't gained a strong foothold in a PC market currently saturated by AMD and Intel. Prior to Apple's entrance, ARM-based PCs were notably slower than their AMD and Intel-based counterparts. However, Apple's M1 chip is proving to be faster than every Intel-based Mac and many Mac desktops.
One way to offer apps for two separate CPU designs is compiling an app containing multiple executables using the Universal binary format. For instance, the app could contain executables for 32-bit and 64-bit Intel processors. The app's header includes information on the executables, so the parent operating system knows which one to run.
Apple enforced this method during its transition from PowerPC to Intel chips so that new apps – not current ones – worked natively on both designs. Apps based on the Universal file format are larger than those compiled for one specific CPU architecture. The new format for combining x86_64 and arm64 executables is called Universal 2.
These two formats don't resolve the issue of running already published apps on a Mac with a completely different CPU design. For instance, an app designed for Macs with Intel processors can't natively run on macOS modified for an ARM-based chip. Something behind the scenes must 'translate' the app. Enter cross-platform virtualization.
2009 Imac Boot From Usb
This technology 'translates' binaries designed for one CPU architecture so they can run on a different operating system or processor. It remaps all operating-system calls given the code differences between one processor design and another. The technology behind Rosetta 2, Transitive Corporation's QuickTransit, uses this method.
Apple's hardware kit for bringing Intel-based apps to Apple Silicon
The DTK is part of Apple's Universal App Quick Start Program for developers to bring their current apps to Apple Silicon Macs and macOS Big Sur. This program includes beta versions of Xcode and macOS, access to developer labs and hardware forums, dedicated technical support, resources, and a hardware kit – the DTK – to test their apps in real-time.
- Processor: A12Z Bionic
- Memory: 16GB
- Storage: 512GB SSD
- I/O: 2x USB-C (10Gbps), 2x USB-A (5Gbps), 1x HDMI 2.0
- Connectivity: WiFi 5, Bluetooth 5.0, Ethernet (1gb)
The kit's A12Z Bionic chip is the same one found in the 2020 iPad Pro. The first Apple Silicon Macs run the M1 processor, which is faster than the A12Z.
Enrolling into Apple's Universal App Quick Start Program cost a non-refundable $500. The program will end one year after the developer accepts Apple's terms and pays the fee. The DTK must be returned within 30 days after the program expires or is terminated.
Early benchmarks surfaced, showing a possible drop in performance in apps using Rosetta 2. Based on the non-native Geekbench 4, Apple's A12Z Bionic chip in the DTK managed an average 828 in the single-core test and an average 2,931 in the multi-core test. Benchmarks only list the four 'big' cores underclocked at 2.4GHz, meaning the translated app may not identify the hardware correctly.
By comparison, the A12Z Bionic chip in Apple's latest iPad Pro scores an average 1,123 in the single-core test and an average 4,701 in the multi-core test. Here Geekbench runs natively on ARM-based hardware, requiring no translation. The app also lists all eight cores.
In early 2021, Apple offered store credit to incentivize developers to return their kits and buy M1 Macs
In February 2021, Apple encouraged developers to return their Developer Transition Kits. The company initially offered $200 of Apple credit and a return-by date of May 31, 2021. However, after developers complained about the relatively low reimbursement compared to the PowerPC-to-Intel transition, Apple increased the offer to $500 store credit.
Apple Boot Usb
The idea was for developers to use the credit to buy a new M1 Mac for continued development. However, those who already bought an M1 machine can use the credit on other Apple purchases.
Thanks again for participating in the Universal App Quick Start Program.
We heard your feedback regarding the 200 USD appreciation credit mentioned in our last email. Our intention was to recognize the tremendous effort that you have put into creating amazing universal apps. By partnering with us early, you showed your commitment to our platform and a willingness to be trailblazers.
So instead of the 200 USD credit that expires in May, we are giving you a 500 USD Apple credit and extending the time you can use it to get a new M1 Mac through the end of the year. If you already purchased a new M1 Mac, the Apple credit gives you the flexibility to purchase any Apple product to help with your app development work.
We'll share details soon about how to ship the Developer Transition Kit (DTK) back to Apple. Note that the DTK will no longer receive publicly available software updates after macOS Big Sur 11.2. We encourage you to return it as soon as possible so that your development work is not interrupted. And once you return the DTK, you'll receive your Apple credit.
Thank you again for making the Mac with M1 launch such a great success.
Apple Developer Relations
Removal
In March 2021, discovered code strings in macOS 11.3 beta 3 suggested that Rosetta 2 'will be removed upon installing this update.' Another line of code advised that 'Rosetta is no longer available in your region. Applications requiring Rosetta will no longer run.'
Imac Usb Boot
Apple has not announced anything regarding Rosetta's removal, and it isn't clear why the company would do that any time soon. As of February 2021, nearly half of all popular macOS apps still needed the translation layer. It's possible the code was merely planning for removal in the distant future, as removing it at this stage would hamstring M1 Macs unnecessarily.
Rosetta was initially designed to translate 'currently shipping' apps built for Mac OS X that ran on PowerPC's G3 and G4 processors. It did not support apps built for older operating systems, like Mac OS 9, Mac OS 8, and so on. It also did not support apps built for PowerPC's G5 processor, although developers could modify G5-specific app code so they could run on Intel-based Macs using Rosetta.
The first version arrived in 2006 in Mac OS X 10.4.4 'Tiger' that was installed on the first Mac with an Intel processor. Rosetta was not included in Mac OS X 10.6 'Snow Leopard' but could be manually downloaded and installed. It was not included or offered in Mac OS X 10.7 'Lion' and newer.
According to Apple, at the time, apps that required 'intense computing needs' weren't compatible with Rosetta, such as apps that dealt with 3D modeling and ray tracing. Word processors and apps that required 'a moderate amount of user interaction' and had 'high computational needs' or used OpenGL were mostly compatible.
In August 2006, benchmarks showed that Mac apps optimized for the PowerMac G5 ran slower than an Intel-based Mac Pro using Rosetta. Native app performance was up to two times better than running the same app through Rosetta, depending on the compared machines. Rosetta was meant to be a temporary 'fix' while developers worked on Universal binaries that ran natively on both CPU architectures.
For example, Photoshop CS2 ran poorly on Intel-based Macs via Rosetta. Adobe resolved the issue by shipping Photoshop CS3 in a Universal binary format, providing separate, native binaries for PowerPC and Intel chips.
Apple's SVP of Software Engineering Craig Federighi boasted during WWDC in 2020 that Rosetta 2 will be even faster, more powerful, and more compatible than the original version for PowerPC. Heavy applications like Maya and games like Shadow of the Tomb Raider will supposedly not experience a performance hit running on Apple Silicon Macs using Rosetta 2.