As a result of some physical, sensory or cognitive deficit, a person may be unable to interpret standard computer output, i.e. a visual display. If computer applications were written such that the output could be re-directed and possibly translated into an appropriate modality (visual, auditory or tactile) and form of presentation, that user would not be handicapped by the technology. Techniques of device independent output, such as the Graphics Kernel System (GKS) provide some relief in terms of alternate visual displays. However, the output primitives they suggest are insufficient for auditory or tactile modalities.
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