Additional FILE commands for Trio Controllers with Firmware v2.0306 onwards will allow
for checks to be made of the size and free space on the SD card fitted into the controller.
Example program below.
DIM sdsize, sdfree, sdused AS INTEGER
sdsize = FILE "DISK_SIZE"
sdfree = FILE "DISK_FREE"
VR(400)=sdsize
VR(401)=sdfree
sdused = sdsize-sdfree
VR(402)=sdused