I had a ZX Spectrum with a Multiface One from Romantic Robot. Prior to that I used to write little bits of machine code by hand using the opcode table in the back of the manual, but with the Multiface it made hacking games so much easier.

Then I started rewriting the loaders, writing trainers for the kids at school. Did a couple of demos, got a Sam Coupe then an Amiga, did some more stuff and ended up working for a living in IT before moving into penetration testing and forensics.