Yes, you get to choose whether you want 16 or 256 subroutines. Most PICAXE's are limited to just 16, others only allow 256. The 18X and 28X allow either ( original versions only allowed on 16 ). With just 16 Gosubs only a 4-bit number is needed to identify each Gosub whereas with 256 that needs to be an 8-bit number so it makes the program code slightly larger and it is slightly slower to execute a Gosub.