You can probably make it happen. If your program uses all the same tricks that worked with 6502 BBC BASIC to reduce the interpreter overhead, the ARM BASIC version will run as well as it can. Then imagine your program does a lot of integer maths with the resident integer variables, multiplication in particular, and (for whatever reason) it needs the full 32 bit integer precision - I'm sure you would stand a chance! 32 bit operations are cheap on the ARM, and it's got a multiply instruction. No such luck with the 6502.