However in ‘remote run’ mode some Scratch blocks no longer have any meaning, e.g. you cannot move a screen sprite, change costume or respond to a keyboard (simply because the PICAXE microcontroller does not have a screen or keyboard connected!) So these types of block should not be used in a remote run program. Within Scratch each script generally starts with a hat block, and then all scripts run at the same time in parallel. The PICAXE-14M2, 18M2, 20M2 microcontrollers each support up to 8 parallel tasks, so the 'remote-run' project should have no more than 8 hat blocks. However this is not generally an issue, as it is quite possible to code useful projects that only actually use one hat block - See more at: http://www.picaxe.com/Software/Third-Party/Scratch/#sthash.ucMQoQLD.dpuf