CURRENTPTR points to current CURRENT. The Forth CURRENT word
doesn't return RAM+2 directly, but rather the value at this
address. Most of the time, it points to RAM+2, but sometimes,
when maintaining alternative dicts (during cross compilation
for example), it can point elsewhere.

NLPTR points to an alternative routine for NL (by default,
CRLF).

FUTURE USES section is unused for now.          

DRIVERS section is reserved for recipe-specific
drivers. Here is a list of known usages:

* 0x70-0x78: ACIA buffer pointers in RC2014 recipes.