Aha. Came home earlier and this was sitting waiting on me.
Its an #amstrad #cpc464 machine code book. I have a pile of pdf books but theres just something right about coding with an old paperback book to hand.
Wasnt till i typed the caption for the image i realised it was quite bizarre. At first glance i thought it was a robot holding a cpc. As its machine code.
But no, its an outboard motor pushing the cpc across the sea... Which now i think about it, is not that unusual for an 80s book cover.