I am trying to remember the name of a book and possibly series I read back early-mid 90's.
The protagonist is a teenage boy, with a mum, dad, and I think a sister. He finds or owns a laptop that has a sentient AI inside it and helps him with his adventures giving him advice and helping him solve problems.
At one point his mother needs money, she also likes to bet on horses. The computer absorbs all the race results of the last year (I think from copies of the racing post being placed on it) and comes up with the answer.
Pretty sure it is also set in the UK
I think there is also a plot line with a villain he has to beat and the threat at one point that the laptop will be destroyed.