Yes, I had used no_init with an old
IAR compiler. Works fine as xdata
alternative. Unfortunately, ICC8051
hasn't such alternative for idata or
data memory classes.

The variables are reset not by compiler,
but by CSTARTUP module, which calls
main(). If you have its source, then
you can disable such feature (I have
done it for bit variables), or, more
sophisticated version -- only after
warm Reset. If you haven't, probably
you can gain some details while
debugging, but writing fully functional
CSTARTUP alternative in this way will
be not easy...

For the IAR compiler mentioned, one
can define typed pointers for data
access, i. e., "#define xptr *(char *)
0x015000" lets to access byte in XDATA
(pointer bits 23-16 specify memory
class).

No ideas for Archimedes compiler, I'm
not familiar with it.