Stephen Hawking's scientific and personal archive, including letters to his family, has been fully cataloged and made available at Cambridge University Library.

The British theoretical physicist told of his computer which "speaks a bit like a Dalek, but with an American accent" in a letter to his parents that is part of the collection.

There is also correspondence demonstrating how Hawking was an active campaigner on issues including disability rights and nuclear disarmament.

The bestselling author of "A Brief History of Time: From The Big Bang To Black Holes" died in 2018 aged 76.

His family donated a wealth of his items to the nation in 2021 and his scientific and personal archive has now been fully catalogued and made available at Cambridge University Library.

There are tens of thousands of pages of papers relating to his work, as well as photographs and scripts from films and TV series like "The Simpsons," "The X Files" and "Futurama" and souvenirs from his encounters with popes, presidents and the public across 113 boxes of archive material.

In a letter to his parents from 1986, which begins "Dear mother and father," Hawking dictates the text using his now famous communication system which he acquired after his tracheostomy the same year.

"I'm writing this letter on my new computer which also speaks but a bit like a Dalek with an American accent," he said in the letter.

"It is very useful for communicating but it is too big to carry around.

"However I have another one which I may be able to get fixed to my chair."

Letters in the archive also highlight the Gonville and Caius College research fellow's campaigning role for scientific colleagues trapped behind the Iron Curtain during the Cold War and for disability rights.

Hawking had been diagnosed with motor neuron disease in 1964 at the age of 22 and given just a few years to live.

In a letter to the Royal Opera House in London, from 1978, Hawking wrote that there were "no facilities at all for disabled people."

He cited the Chronically Sick and Disabled Persons Act 1970 and demanded better access to the building.

In a further letter, in 1982, he told Sir John Tooley, General Director of the Royal Opera House: "I wrote to you a few years ago about the lack of facilities for disabled people in the Royal Opera House.

"I knew that you had recently spent a lot of money on improvements so I expected the situation would now be better.

"However, on my visit to the Meistersinger last night I found the arrangements were just as bad as ever.

"I had to be carried to my seat by two attendants, carried out and back again during the interval and carried out at the end when they succeeded in dropping me.

"It was not the fault of the attendants, they did their best, but there is no proper provision for the disabled."

Hawking archivist Susan Gordon, who has spent the past 28 months cataloging the collection, said: "The Library's Stephen Hawking Archive documents not only his journey to becoming one of the preeminent theoretical physicists of his time, but also how his efforts to communicate science to a general audience catapulted him to the status of pop cultural icon.

"The papers also reveal how the same tenacity Hawking displayed in his professional career was applied to advocating for causes he believed in, including disability rights and accessibility.

"He started using assistive technology for communication, both written and spoken, during the digital revolution and it was fascinating to see how he interacted with developments in computer technology.

"He was a very early adopter of the personal computer, with bespoke modifications and programs made to assist him and was also involved with researchers and inventors pioneering alternative communication technologies.

"The archive will be a unique resource for researchers interested in Hawking’s scientific work and academic life, his personal life, popular science communication, disability rights, assistive technology and celebrity.

"No single thread sits in isolation, they were interwoven in the tapestry of Hawking's life, including glimpses into how he felt about their convergence.

"I hope the release of the catalog and the improved access it provides will allow others to be as rewarded as I was by interacting with the archive."

The catalog publication and public availability of the Hawking Archive coincides with a special collection of Hawking papers in the latest issue of the Science Museum Group Journal.

The Science Museum is home to the esteemed scientist's former office - a unique collection of more than 1,000 objects transferred from the University of Cambridge in 2021.

Hawking's family wanted his work to be made freely available to future generations of scientists and struck a landmark Acceptance in Lieu (AIL) agreement with the U.K. government, the Science Museum Group and Cambridge University Library.

The agreement means that thousands of pages of Hawking's scientific and other papers remain in Cambridge, while objects including his wheelchairs, speech synthesisers and personal memorabilia are displayed at the Science Museum.