Hopefully, a Lisp implementation that doesn't use tag bits for type & GC. At those low machine word lengths, every bit is precious. E.g. if you take 2 bits for

Hopefully, a Lisp implementation that doesn't use tag bits for type & GC. At those low machine word lengths, every bit is precious. E.g. if you take 2 bits for type and 1 for GC, you're left with 5 bits, or a total of 32 unique values representable by the machine (30 if you take take out NIL & T.) Useful for a desk calculator, not much else.