The thing that has always impressed me about the ARM1 is that they didn't just take the RISC model from the papers they read: they adapted it to suit their own

The thing that has always impressed me about the ARM1 is that they didn't just take the RISC model from the papers they read: they adapted it to suit their own needs. Adding the barrel shifter, conditional execution, removing features that made the design more complex, and squeezing it into a gate count that meant that they could produce it at an acceptable cost. As Wilson said later - "MIPS for the masses" - and not for workstations. It wasn't just a technical achievement it was a commercial achievement too - although Acorn failed to make use of it of course.