Science Fiction book - Read around 1985 - Starts with the main character with no memory he has a smartwatch that talks to him.

[Charles]

Science Fiction book - Read around 1985 - Starts with the main character with no memory he has a smartwatch that talks to him. This happens on a large Earth-based space station. A virus has decimated the Earth. He has to find out why his memory has been wiped, who he is. I seem to remember the space station as being a very large rotating environment with simulated gravity. He does get his memory back and saves the rest of mankind.

Does anyone know who wrote this book and it's title. TIA