Antiques Roadshow is at Alexandra Palace, the birthplace of television, for this special edition of the programme to celebrate 100 years of BBC broadcasting.Ronnie Archer-Morgan is thrilled to revisit the world of children's television with Baroness Floella Benjamin, together with Humpty and Jemima from Play School, while Fiona Bruce gets to lay her hands on the original shooting script from legendary comedy series Hancock's Half Hour, brought in by actor and collector Neil Pearson.Also turning up at Alexandra Palace is none other than Del Boy's green Ford Capri from the hit sitcom Only Fools and Horses, complete with furry dice and hooter, and we're also joined by actress Anita Dobson, who shows off some of the outfits worn by her iconic EastEnders character, Angie Watts.One collector reveals an impressive collection of Doctor Who autographs, while a former natural history cameraman reveals some of the tricks involved in covert wildlife filming.Expert Will Farmer gets the chance to play quizmaster when he comes face-to-face with the original Mastermind chair, brought in by Sally Magnusson, daughter of the show's original host. And Fiona Bruce gets to meet one of her heroes, former BBC news correspondent Kate Adie, who reflects on her time reporting from the world's hotspots.