In the mid 1980 s, a ‘couple of academics wearing startup-company hats’ were developing a retargetable C compiler. The most prolific target for this compiler was the ARM processor, a novel RISC architecture initially designed by Acorn and subsequently developed by Arm with input from its partners. In this paper, we will review 1980 s compiler technology and see how the Norcroft compiler significantly advanced the state of the art, particularly highlighting the friendly error messages, flexible intermediate representation and graph-colouring register allocation. We will review the reach and legacy of the Norcroft compiler over the past four decades.