The most important restriction is the RAM size: the generated program file
(without COMMON blocks and stack) may be as large as the largest remaining
free memory block after loading the linker. On the other hand it's also
possible to generate a program with very large COMMON blocks or stack, that
runs out of memory while loading or executing.
The max. number of subroutines is restricted to 3000, the max. number of
COMMON blocks is 1500.