Technology

New Apple operating system and accessibility features

Summary: A report on the accessibility features in the new operating system for Apple Macintosh computers.

• Apple OS X 10.4 (Tiger)
• Magnification with Zoom
• Screen-reading with VoiceOver
• Further information

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Apple OS X 10.4 (Tiger)

The latest version of the software that Apple supply with their range of Macintosh computers, OS X 10.4 (Tiger), has built-in screen magnification and screen reading features which allow people with sight problems and others to use a Mac computer without having to purchase additional assistive programs. Tiger may be preinstalled on a new Mac machine or can be purchased as an upgrade for an older one. Either way, if the machine can run Tiger, it can have these features. Tiger also contains universal access features to help those who may have trouble using the keyboard or mouse or hearing alert sounds.

Apple OS 10.4 requires a Macintosh computer with the following specification:

• PowerPC G3, G4 or G5 processor
• Built-in FireWire DVD drive for installation
• 256MB of RAM
• 3GB of available hard disk space (4GB if you install the developer tools).

Apple makes a range of desktop and notebook machine. The new Mac Mini is a sandwich-box sized unit that can be connected to an either a Mac or PC monitor screen and to most USB keyboards and mice. Macs are said to be more reliable, easier to learn to use and less prone to viruses and other nuisance programs than Windows-based computers.

Tiger includes several accessible applications including Finder, Mail, Safari (for web browsing), TextEdit (which can open, edit and save Word documents), iChat AV, Preview (a PDF viewer), Terminal, Automator, Chess, and many utilities. Other included programs play DVDs (iDVD); manage a music collection (iTunes); manage a photo collection (iPhoto); compose music (Garage Band) and much more. Programs written for Tiger, conforming to Apple’s guidelines, should magnify and speak without further adaptation. However, programs that pre-date Tiger, such as iWork and Microsoft Office for Mac, may work with magnification but probably not with speech. It is hoped that as new versions are released these programs will become more accessible.

For people used to Microsoft Windows with a magnification or screen-reading program, Apple’s software will feel somewhat different and may take some time to master.

Magnification with Zoom

If you have a sight problem, Mac OS X Tiger provides a range of options to help you see what’s on screen more easily. The magnification level can be incrementally increased and decreased using the keyboard from no magnification to over twenty times (although beyond a certain point the text loses some of its sharpness). Minimum and maximum pre-set levels can be set allowing an easy and effective way to switch from a high level for detailed work to a low level for an overview of the screen, and back again. Tapping the increase magnification keystroke will snap to the pre-set level and likewise for the decrease magnification key. The same keystrokes can then be used to refine the level.

The screen colours can be inverted or changed to shades of grey. The contrast can also be adjusted with keystrokes. The magnified screen image can be set to continuously move with the mouse pointer, move only when it nears the edge of the visible screen area or keep it centred in the visible portion of the screen.

Zoom provides full-screen magnification only – there are no magnifying-glass or split-screen modes.

Tiger’s Universal Access feature allows for the size of the mouse pointer to be increased over a fairly wide range, and for keys to be used to control the mouse.

Screen-reading with VoiceOver

For those who need speech output from their computer, VoiceOver is Apple’s answer. It reads aloud the contents of files including web pages, mail messages and word processing files, provides a comprehensive audible description of your workspace and includes a rich set of keyboard commands that allow you to navigate the Mac OS X interface and interact with application and system controls.

VoiceOver uses synthetic speech to read the contents of the screen. This is usually the contents of what Apple calls the VoiceOver cursor which normally equates to the currently focused piece of text or control. The VoiceOver cursor allows for interaction with items as well as describing them. For example, buttons can be pressed, sliders dragged, dials turned, check boxes enabled and disabled, radio buttons selected. VoiceOver also provides additional key commands for faster navigation and to request information such as text attributes like font and style, the names of running applications the location of the mouse cursor, and much more.

In addition to keyboard navigation and hot keys, VoiceOver also provides Item List and Link List choosers to allow even faster navigatation. VoiceOver instantly scans the HTML area of the current document and displays in alphabetical order, every URL (or link) found on that page. You arrow through the list sequentially to select and the VoiceOver cursor moves there directly. You can also filter the list of links by typing a few characters instead of, or in addition to, using the arrow keys. In just a few keystrokes you’ll be able to navigate to any link directly. The Item List works the same way but includes every visible item in an application as well as links so you can navigate anywhere in the program directly with just a few keystrokes.

Keystrokes are also provided to perform functions in Tiger which would otherwise require use of the mouse such as highlighting the menu bar or the Dock – where shortcuts to commonly used programs can be stored.

A set of synthetic voices is provided and additional voices can be purchased. The rate and pitch can be adjusted, as can the reading of punctuation and text attributes such as bold and italics.

VoiceOver can be set to speak straight after the Mac starts up or during the log-in process. Once logged-in VoiceOver will be running for those users who have asked for it and not for others. This allows family members and co-workers to use the same machine without the inconvenience of having to manually start of stop VoiceOver each time they log-in.

Further information

Macvisionaries is a user group and mailing list for blind and partially sighted Mac users.

This document is based on information available from Apple accessibility website and several weeks experimenting with a machine.

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Content author: technology@rnib.org.uk

Last updated: 08/04/2008 18:38