There's an HPGCC v3 which you can download from
<
https://www.hpcalc.org/details/6514>
The main difference, as I understand it, is that v2 only allows you to
write programs that completely take over the machine. v3 - in
combination with a slightly modified HP50G ROM - allows you to write ARM
machine code functions that look and behave like standard userRPL
functions i.e. take values from and leave results on the stack.
If you're writing games or intending to completely re-puupose the
machine then it doesn't much matter. But if you want to accelerate some
slow RPL routines then v3 is the obvious choice.
HTH
--
Bruce Horrocks
Surrey
England
(bruce at scorecrow dot com)