Veterans have gathered at Bletchley Park near Milton Keynes to celebrate the 70th anniversary of a computer credited with stopping Hitler.
ITV recently returned to film the second series of its hit drama, The Bletchley Circle. Anna Maxwell Martin stars in the thriller.
Alan Turing is expected to receive a full parliamentary pardon.
Auditions are being held today for a living history project at the Bletchley Park wartime code-breaking centre in Buckinghamshire.
Local actors will play characters that were at the centre in 1941, when Britain was in great peril. They will be performing during half term next month.
Bletchley Park is to take centre stage in a new television drama on ITV.
The estate, near Milton Keynes, is world famous for its role in breaking the German Enigma and Lorenz codes during the Second World War - often attributed to shortening the conflict by between two to four years.
As a hub for pioneering computer science, Bletchley Park is also often deemed to be the birth place of the modern-day computer.
The drama, The Bletchley Circle, will transport the site back to the 1940s and 50s for a two-part story to be shown on ITV next week.
A letter sent from Alan Turing to his mathematician friend Norman Routledge shows the codebreaker's worries and "distress" ahead of pleading guilty to gross indecency in 1952.
An excerpt from the communication is printed on the website Letters of Note, citing a Turing biography by Andrew Hodges.
I've now got myself into the kind of trouble that I have always considered to be quite a possibility for me, though I have usually rated it at about 10:1 against.
I shall shortly be pleading guilty to a charge of sexual offences with a young man.
The story of how it all came to be found out is a long and fascinating one, which I shall have to make into a short story one day, but haven't the time to tell you now.
No doubt I shall emerge from it all a different man, but quite who I've not found out.
Glad you enjoyed broadcast. Jefferson certainly was rather disappointing though.
I'm afraid that the following syllogism may be used by some in the future.
– Letter from Alan Turing to Norman Routledge
Turing believes machines thinkTuring lies with menTherefore machines do not think
Yours in distress,
Alan Turing revealed he was gay to the authorities by falling for an "old police trick," New Statesman legal writer David Allen Green reports.
Reporting a theft to police in 1952, Turing was forced to fabricate details of the account to conceal his relationship with a man.
Asked to repeat the account a week later by police, Turing was unable to accurately remember some of those fabricated details, Allen Green writes.
On realising his lies had been exposed, the brilliant mathematician produced a five-page letter admitting untruths as well as describing graphic details of his homosexual relationship.
The statement was enough for police to convict Turing and arrest his partner.
Second World War codebreaker Alan Turing, has been given a posthumous royal pardon for a 61-year-old conviction for homosexual activity - still an offence in the UK in the 1950s.
The Cambridge mathematician has been hailed a national hero for his work to help break the German Enigma Code at Bletchley, near Milton Keynes during the war.
News of the royal pardon granted posthumously to Alan Turing has been applauded as a "just reward" for the code-breaker.
Iain Stewart, Conservative MP for Milton Keynes South, who was involved in the campaign to secure a royal pardon, said: "Alan Turing was an incredibly important figure in our history. He was the father of computer science and the originator of the dominant technology of the late 20th century."
Gay rights campaigner Peter Tatchell said that the granting of the royal pardon was "long overdue" and called for the same treatment to be given to others convicted in similar circumstances.
He said: "Singling out Turing just because he is famous is wrong. Unlike Alan, many thousands of ordinary gay and bisexual men who were convicted under the same law have never been offered a pardon and will never get one.
"An apology and pardon is due to another 50,000-plus men who were also convicted of consenting, victimless homosexual relationships during the 20th century."
Ed Miliband has spoken of his "delight" that Alan Turing has received a Royal Pardon.
Reacting to the news on Twitter, the Labour leader posted:
Alan Turing was a hero and an extraordinary academic - his work helped win World War II. I'm delighted he has received a Royal Pardon.
Dr Alan Turing died of cyanide poisoning and an inquest recorded a verdict of suicide, although his mother and others maintained his death was accidental.
There has been a long campaign to clear the mathematician's name, including a well-supported e- petition and private member's bill, along with support from leading scientists such as Sir Stephen Hawking.
The pardon under the Royal Prerogative of Mercy will come into effect today.
The Justice Secretary has the power to ask the Queen to grant a pardon under the Royal Prerogative of Mercy, for civilians convicted in England and Wales.
A pardon is only normally granted when the person is innocent of the offence and where a request has been made by someone with a vested interest such as a family member.
But on this occasion a pardon has been issued without either requirement being met.
David Cameron has paid tribute to Alan Turing for his role in "saving Britain in World War Two" after the famous code-breaker was awarded a a posthumous royal pardon.
The Prime Minister said: "Alan Turing was a remarkable man who played a key role in saving this country in World War Two by cracking the German Enigma code.
"His action saved countless lives. He also left a remarkable national legacy through his substantial scientific achievements, often being referred to as the father of modern computing."
The Bletchley Park computer pioneer Alan Turning has been given a posthumous pardon more than 50 years after being prosecuted for homosexuality.
Turing is widely considered the father of computer science. He went to Cambridge University and during the Second World War he was based at Britain's codebreaking headquarters near Milton Keynes.
He was convicted of in 1952 when homosexuality was illegal in the UK; he committed suicide two years later.