Britain's code-cracking and computing heritage has won a lifeline in the form of a donation from English Heritage.The grant of £330,000 will be used to undertake urgent roof works at Bletchley Park - where Allied codebreakers worked in World War II.Discussions are also in progress on a further three-year, £600,000 funding programme for the historic site.The donation follows efforts to highlight the dilapidated state of the huts and other buildings at Bletchley.The rooms of the Grade II-listed mansion, replete with painted ceilings, timber panelling, and ornate plasterwork, are at risk because the roof has been patched rather than renovated so many times during the 130 years of the mansion's history.The work funded by the grant is projected to finish in March.