Basically, if you change acc2168´s port 78 to return 0x20 instead of 0, a siren sound should be heard, but somehow with the new timer code, what you hear on the pb410 using interpreter is some garbage, but still works fine on dynarec, but its sound is distorted unless ISA_CYCLES(8) are subtracted on pit read/write.
It worked fine on both interpreter and dynarec using the old timer code.