IBM has a program prototype that enables blind people to operate computers by choosing from on-screen pictures and icons via an interpreter that reads the images aloud. The program is called Screen Reader for Presentation Manager and unlike existing devices that convert words and numbers into synthesised speech, the new program recognises internal coding used to form pictures, and converts that data into digital information that enables the speech-reader to recite what it sees. This provides blind people with access to a graphical user interface, which is increasingly important as personal computing moves away from keyboard-oriented computing to standards like OS/2 Presention Manager or Microsoft’s Windows 3.0 and X Window for Unix. For blind programmers, the move to new operating systems is a threat since they can’t navigate images or pull-down menus, and many fear that their jobs are at risk, the New York Times reports. To access Windows and similar environments, developers have to overcome a number of obstacles, and most significant is how to translate the data on screen into speech. In a text or character-based system, that function is performed by a text-display buffer, the part of computer memory that stores a number for each position on the screen. A speech-reader program directs the computer to send the number from the buffer to a voice synthesiser to be spoken, and the computer reads back and provides spoken directions. However, graphics-based systems do not have a text-display buffer, and the graphics are represented in memory by dots. To form a letter, a block of dots is painted on the screen, and although it may look like a letter, there is no way to tell the voice synthesizer to read it since it does not have a numeric representation. Both IBM and Berkeley Systems Inc have developed models that intercept the commands that draw and erase text before the commands reach the screen, and to maintain a special text buffer. From this buffer, the off-screen model, information can be translated and sent to the synthesizer. Berkeley Systems’ prototype has resulted in a product called Outspoken which enables blind users to work with an Apple Macintosh. The Trace Res earch and Development Center at the University of Wisconsin is also de veloping a graphic interface for the Macintosh. It is said to be more sophisticated than Outspoken and incorporates a device that ena bles users to feel the screen imag es. The virtual tactile mouse uses vibrating pins that enable the user to move around the screen and feel the dimensions and edges of images..pl 63
