This middle-grade novel was from sometime between 2000 and 2016, I believe. It was by an American or British author, who died before 2016, as mentioned on the back cover.
- The protagonist was a 10/11 year old boy who described his mind as being wired differently, like a computer with a different operating system; later he said he had a mental disorder such as autism or Asperger's.
- He was from the US.
- He made a friend with a boy of a similar age from England.
- The British boy had a sister, I believe, and maybe was related to the main character.
- This friend frequently used the British slang word "mosher", saying something like it meant "a right cool dude".
- I think it maybe took place in England.
- If it did, there was some sort of a scene where the characters went on the London Eye, but that is likely confused with another book.