sorry about that, it's a doc bug, the correct proc in crustyBASIC programs is RAND(). RND is a dialect thing, I'll update the docs, thanks for the report!
LFSR_NEXT etc are not fully implemented in 1.2.0, they are in 1.3.0 which is coming out later this week. A metric ton of fixes, updates and 2 new targets. :)
not currently as RAND() maps differently to all the targets. I will put that on my TODO list. LFSR_SEED/LFSR_NEXT/LFSR_RANGE in the next release will be a seed-able pseudo rng.
