Speech Plus Prose 2000 Speech Synthesizer — original model used by Stephen Hawking?

The Speech Plus Prose 2000 is a speech synthesizer from 1982 based on the same algorithm as the DECtalk. This is the same brand/model of speech synthesizer originally used by the physicist Stephan Hawking. The Prose 2000 is a multibus card, but can be operated as a standalone speech synthesizer as well.