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Archive for February, 2018

by Tom Nelson

Last week, we started our foray into the Mac’s Accessibility features with an overview of the services available, and a look at the General category, which provides quick access to many of the Accessibility features. If you would like to review Part One of this series, you can find it at:

macOS 101: Getting Started With the Mac’s Accessibility Features.

In Part Two, we’re going to look at the Vision category, including:

  • VoiceOver: The Mac’s built-in screen reader.
  • Zoom: The ability to enlarge or shrink the view on the Mac’s display.
  • Display: Options to enhance the display for easier viewing.
  • Speech: Using the Mac’s speech options to read alerts, speak text, and modify characteristics of the voice used in the VoiceOver application.

VoiceOver
VoiceOver is the Mac’s screen reader app, though it does quite a bit more than just telling you what’s happening on the screen. It provides voice descriptions of each onscreen item, suggestions about how to use them, supports 35 languages and braille display, and offers a wide range of voice options, including the ability to control your Mac with just a keyboard.

Once VoiceOver is enabled, the caption panel will be displayed. Screen shot © Coyote Moon, Inc.

VoiceOver is often thought of as an app that’s included with the Mac OS, but actually it’s a core service of the operating system. This allows third-party developers to integrate VoiceOver into their apps to provide simplified navigation with their products.

To configure and use VoiceOver:

Launch System Preferences by clicking on its Dock icon, or by selecting System Preferences from the Apple Menu.

In the System Preferences window that opens, select the Accessibility preference pane.

If you have Siri up and running, you can say “Hey Siri, open the Accessibility preference pane” as an alternative.

In the Accessibility preference pane, select VoiceOver from the sidebar.

The VoiceOver options will be displayed in the configuration pane.

To enable Voiceover, place a checkmark in the Enable VoiceOver box, or use the command + F5 keyboard combination. You can also use Siri by speaking, “Hey Siri, turn on VoiceOver.”

VoiceOver can also be turned on using the Accessibility Shortcut panel. See Part One of this series, macOS 101: Getting Started With the Mac’s Accessibility Features, for details.

Once VoiceOver is enabled, a caption panel will appear in the bottom left corner of the screen. Within the panel, the text that VoiceOver speaks will be displayed.

VoiceOver will speak and display descriptions of each element on the screen as you interact with them. Besides speaking a description, the VoiceOver caption panel will provide hints and instructions for how to interact with the various elements you encounter.

VoiceOver provides a large number of ways to interact, including an extensive collection of keyboard shortcuts, gestures, and other input methods. A complete list of all the ways to interact are a bit beyond the scope of this overview, however, VoiceOver has a built-in training system that takes the user through the process of using the Mac via VoiceOver commands.

To launch the VoiceOver training, return to the Accessibility preference pane.

Make sure VoiceOver is selected in the left-hand pane, then click the Open VoiceOver Training button.

The training instructions will be displayed. You can move through the training pages using the arrow keys on the keyboard. Use the Escape key to end the training.

Apple also has a VoiceOver Getting Started Guide that I highly recommend. The guide is also available in an English Unified Braille version, and an embossed braille version is available to order.

The Getting Started Guide covers working with text, navigation, VoiceOver basics, working with tables, navigating the Internet, and much, much more.

VoiceOver tip: Control + Option is the default set of VoiceOver keyboard modifiers, and is referenced in most VoiceOver keyboard commands. If you’re using OS X El Capitan or later, the caps lock key also works as the VoiceOver modifier. It lets you press a single key, and when VoiceOver is enabled, the caps lock key doesn’t function as a normal caps lock anyway.

The VoiceOver Utility allows you to customize VoiceOver to meet your needs. Screen shot © Coyote Moon, Inc.

The last component of VoiceOver we will cover is the VoiceOver utility, which provides a way to customize VoiceOver to work the way you would like it to. You can customize the following:

  • Verbosity: Specify the verbosity level for speech, braille, text, announcements, and hints.
  • Speech: Select the voice, rate, pitch, and volume, as well as how certain text is pronounced.
  • Navigation: Customize how VoiceOver works with cursors, groups, redundant items, and more.
  • Web: Control how web pages are navigated.
  • Sound: Change basic sound parameters.
  • Visuals: Control VoiceOver cursor size and movement, caption panel size, braille panel font size and color, and menu font size.
  • Commands: Allows you to assign VoiceOver commands to keyboard characters
  • Braille: Customize settings for an attached braille display.
  • Activities: Create sets of preferences for use with specific activities.

To access the VoiceOver Utility, return to the Accessibility preference pane.

Make sure VoiceOver is selected in the left-hand pane, then click the Open VoiceOver Utility button.

You can also ask Siri to do it by saying, “Hey Siri, open VoiceOver utility.”

VoiceOver tip: Use the Speech options in the VoiceOver utility to try out different voices. Alex Compact and Fred are popular VoiceOver voices to use. Be sure to try a voice with different speaking rates and pitch to find one that intones clearly.

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by Tom Nelson

This is the first in a series of articles that will explore the Mac’s built-in accessibility features that are designed to make using a Mac as easy as possible for everyone. Is the mouse cursor a bit too small? You can change the cursor size within the Accessibility preference pane. Is a standard keyboard difficult or nearly impossible to use? Once again, within the Accessibility set of features you can modify how a standard keyboard works, or create an onscreen keyboard you can control with head or eye tracking technology.

AccessibilityIcon

The range of capabilities in the Accessibility preference pane is so large that one article wouldn’t do them justice. So, let’s get started with a quick overview and a look at some of the more general settings and capabilities.

Accessibility Overview
The Accessibility API became an official part of the Mac with the release of OS X 10.2 (Jaguar), though it was known then as Universal Access. The name change to Accessibility didn’t occur until the release of OS X 10.8 (Mountain Lion). While the initial release lacked many standard features that are taken for granted today, it did include tools for those with partial vision loss, though in its original offering it lacked an important tool for those with visual impairment: a full-screen reader.

With each release of OS X, and later, macOS, the accessibility features grew and were refined to bring equal access to the Mac to all users.

As we delve into the Accessibility options it’s important to point out that not every feature we mention is available in all versions of the Mac operating system. Apple moved the location of some features around within the Accessibility preference pane from time to time. Where possible, I’ll attempt to mention if a feature has been moved, and where it used to be located. I’ll also concentrate on the versions of the Accessibility preference pane starting at OS X Mountain Lion and going forward, with emphasis on the version included with macOS High Sierra. The earlier versions, known as Universal Access, have many of the same features, but the user interface is different enough to make including the older versions cumbersome at best. If I miss any changes, be sure to leave a comment below, letting us know.

The Accessibility options are currently organized into five categories:

General: This category was added with macOS Sierra. The general pane is primarily used to select which Accessibility options will be available in the Accessibility Options Shortcut panel.

Vision: This category was originally called Seeing, but it underwent a name change in OS X Yosemite. This group includes Accessibility options useful for anyone with vision-related impairments.

Media: The Media category was added in OS X Yosemite. It allows the use of subtitles and spoken descriptions in media that supports the feature.

Hearing: Basic audio controls involving alerts and converting all stereo sound to mono.

Interacting: This is the largest accessibility category and covers all the user interface elements used to interact with the Mac, including keyboard, mouse or trackpad, Siri, Dictation, and Switch Control.

The General settings are used to specify which options will be displayed in the Accessibility Shortcut pane. Screen shot © Coyote Moon, Inc.

Accessing the Accessibility General Category
All of the Accessibility options are accessed through the Accessibility preference pane. To bring up the pane, do the following:

Launch System Preferences by clicking on its Dock icon, or selecting System Preferences from the Apple menu.

Select the Accessibility preference pane.

The Accessibility preference pane will open, displaying a sidebar on the left-hand side that contains a list of all of the Accessibility options, organized by category. On the right is the configuration pane, which allows you to control how each of the accessibility options is used.

In the sidebar, select the General item. The General category was added in macOS Sierra to support a new feature: the Accessibility Shortcut panel. You may need to scroll to find the item. If you’re using an earlier version of the OS, you can skip down to the Accessibility Status section, below.

In the configuration pane, you’ll see a list of accessibility services that will be shown in the Accessibility shortcut pane when it’s displayed. You can select which items you wish to have shown by placing a checkmark in the corresponding box.

Note: Placing a checkmark in the box doesn’t enable the feature; it only allows it to appear in the Accessibility Shortcut panel.

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by Tom Nelson

I’ve heard it said that an SSD or hard drive that isn’t used for extended periods of time will likely have performance issues, or worse, actually lose data in the span of a few years. I’ve even heard it said that SSDs could lose their information in less than a year, and in the worst case, within a few days.

Of course, I’ve heard a lot of things, and not all of them bear up well when looked at closely. So, let’s find out if we need to keep exercising our storage devices to maintain information and performance.

Data Retention
The ability of a storage device to keep the data it contains intact is known as the data retention rate. The actual rate cited for various devices is predicated on the storage device being non-powered, undergoing no refresh of the data it contains, and being kept in an ideal storage environment, usually mentioned as around 25 C / 77 F.

Under those ideal conditions, hard drives are predicted to be able to retain their data for 9 to 20 years. The long range is due to the different architectures used in the manufacturing of modern hard drives.

SSDs (Solid State Drives) have a reputation for having a very low data retention rate. Numbers commonly cited suggest one year for consumer grade SSDs, and as low as one week for enterprise class SSDs.

If you believe the reputation is true, then SSDs would need to be exercised at defined intervals to ensure they keep the data stored intact. However, is that reputation valid? We’ll find out in a bit, but first, let’s look at hard drives.

Hard Drive Failure Mechanisms
The length of time your data will be retained on a hard drive in storage, one that isn’t powered and kept in a controlled environment, is based on four primary factors:

Magnetic Field Deterioration: Permanent magnets generally lose their field strength at the rate of 1% per year. After 69 years, the field strength would have dropped by 50 percent. That much field strength loss will likely lead not only to general data corruption of the stored data, but also to the loss of the index tracking marks which tell a drive where a sector starts and stops. So, not only is the stored data lost, but the ability to read the drive may be gone as well.

Magnetic Field Corruption: Magnetic fields external to a stored hard drive can adversely affect the stored data by altering the charge at one or more locations on the drive’s platters. Magnetic disruption can be caused by nearby high power magnets, motors, or even by unusually strong geomagnetic storms caused by solar mass ejections on the sun.

Environmental Conditions: Humidity and temperature ranges for stored hard drives differ by drive manufacturer. Western Digital recommends storing their hard drives between 55 F and 90 F. Extreme high temperatures increase the risk of damaging mechanical components, such as warping heads or platters, while extreme cold temperatures can cause bearing failure, or allow the spindle and motor to become misaligned. (Related: Keep Your Electronics Warm and Safe This Winter)

Mechanical Failure: Even with the proper storage conditions, mechanical failure, such as the platters failing to spin up due to motor failure, or spindle bearing failure, can happen. These types of failures tend to occur when drives are stored for exceptionally long periods of time without ever being powered on.

Mitigating Hard Drive Storage Failures
Of all the possible issues with hard drive storage, two of the most common ones can have their effects mitigated by exercising the drive. In the case of mechanical failure over long time frames, the simple approach is to power on the drive occasionally, ensuring the bearings, motor, and grease are all warmed up, and preventing them from becoming stuck in one location.

Refreshing the stored data can reduce magnetic field deterioration. This would require the drive to be powered on and connected to a computer system. Reading the stored data isn’t enough; to refresh the magnetic charge the data must be read and then rewritten to the drive. An easy way to accomplish this, assuming there’s enough room on the drive, would be to copy the content to a new location on the drive, or create a disk image and copy that to a new location on the drive. Another option would be to clone the drive to another storage device, and then clone the drive back again.

How often you should perform this exercising of a hard drive is difficult to say, but once a year or once every two years would be a good starting point. While a longer time frame is actually possible between exercising a hard drive, the task tends to get overlooked when the time frame becomes longer. It’s much easier to remember a yearly exercise routine than to try to remember to perform this task once every x number of years.

Screen shot © Coyote Moon, Inc.

SSD Failure Mechanisms
A few years back, a presentation was made at the JEDEC Standards Committee for solid state drive requirements at which a slide showing expected data retention rates for SSDs in a powered-off stored state was shown. That slide indicated the very poor ability of an SSD to retain data for any length of time when powered off. Specifically, it mentioned the following data retention rates:

Consumer grade SSD: 1 year at a 30 C storage temperature.

Enterprise grade SSD: 3 months at 40 C storage temperature.

In both cases, as the power off storage temperature increases, the data retention rate falls. In the case of consumer grade models, data retention can fall at one month at 50 C, while enterprise class SSDs can see less than one week at 50 C.

Pundits quickly picked up this information and it spread around the Internet, leading to the poor reputation SSDs can have for data retention when powered off. The problem is that it’s simply not true. The information being conveyed in the original presentation pertained to a worst-case scenario, one where the SSD under question has nearly reached its end-of-life, and has had its P/E count (Program/Erase cycle count) reach the point where data cells would start showing write failures. But when the background information was removed and only the information on the slide was presented, a legend, or at least a reputation, was born.

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by Tom Nelson

Do you have a few USB flash drives lying around? Chances are you have at least a couple, or maybe even a small drawer full of them. In my case, I have about a half dozen, with no specific use assigned to them. That means I have a source of flash drives for trying out a few unusual uses for these handy take anywhere storage devices.

Image courtesy of MacSales.com

There are lots of uses for flash drives, including using them as an easy way to copy files between computers, as intermediate storage for photos, music, and videos, and what may be a primary use this time of year, sending tax return data to and from your tax preparer.

But those are more mundane uses. In this article, we’re going to take a look at four more interesting uses for flash drives you’re currently not using.

RAID 0 Security Array
A USB flash drive can make a surprisingly versatile and reasonably fast Striped RAID array (RAID 0). All that’s needed is a powered USB hub with enough ports to accommodate the flash drives you’re going to connect. The speed you can get out of a USB flash RAID 0 array is based on three factors: the number of flash drives you use, the speed of the flash drives, and the speed of the USB interfaces.

You can use flash drives to create a small but reasonably fast striped RAID array. Screen shot © Coyote Moon, Inc.

Assuming you’re using USB 3.1 gen 1 ports, hubs, and flash drives, the maximum theoretical speed is 5 Gbps, which you’re not likely to ever actually see, but it does set an upper limit. In actual use, the flash-based RAID array is going to be limited chiefly by the write and read speeds of the USB flash drives. Some of the fastest flash drives available can have write speeds a bit better than 150 MB/s, and read speeds coming close to 200 MB/s. However, most USB 3.1 flash drives have much more modest write and read speeds, with sub 25 MB/s write speeds and sub 100 MB/s read speeds being a bit more typical.

Even with the slower flash drives, if you put enough of them together, you can get pretty surprising write and read performance out of them in a RAID configuration.

To build the USB flash drive RAID array, plug as many flash drives as you have on hand into a USB hub. It’s best if the flash drives are the same size, speed and manufacturer, but it’s not a requirement.

You can use the RAID Assistant built in to all versions of the Mac OS (except OS X El Capitan), or you can use SoftRAID or SoftRAID Lite to create the RAID 0 array.

Even this modest three flash drive RAID set achieved write speeds of 70 MB/s and read speeds of 240 MB/s. Not bad for scrounging together some leftover parts. Screen shot © Coyote Moon, Inc.

You can use your USB flash-based RAID array for just about anything you would use a normal external RAID for, but these two uses may be of interest:

As an old-fashioned secure data storage system: Data stored on the flash array is effectively divided between the flash drives that make up the array. Split those drives apart and store them separately and the data on them can’t be reconstructed. Bring all of the flash drives back together and you can access the information they contain. For even more security, you can encrypt the array using the FileVault encryption options built into your Mac.

As a fast array for scratch space for graphics, audio, or video apps: Be a bit careful here, because if you’re using low-cost flash drives, the write speed may be a bit low for this type of use. On the other hand, the read speed is probably quite good.

As with any RAID 0 storage system, there’s a danger of data loss should one of the drives fail or is lost, so be sure to use a backup system if you plan to use this RAID array beyond just trying out the idea.

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