Two quickies! I hope!

Does Ada have routines for displaying numbers in Hex or Octal (preferably
Hex)?  I would write a recursive function to do this, but recursion isn't
something i'm confident with.  It'd go something like divide by 16 taking
remainder each time and append the result to front of string, stopping when
number is 0,  i think.  It'd be nice if Ada did it for us though.  Most of
the books only mention mod/integer display in decimal, and i can't afford
that �57.00 book covering the 'whole' of the Ada language and standard
libraries.  {books are really expensive -- i've been out �400-�500 on books
this academic year alone. I moan too much!!!}

I'm using mod types to simulate registers in the RISC machine.  I'm about to
implement arithmetic operations but i've thought of a problem.  How do i
detect overflow?

e.g.
    say it was 1 byte reg

    25*158 is too big.

    12+254 is too big also.

but mod types wrap round, so how do i detect the overflow?  This is a
bugger, cos' i've implemented quite a bit of the RISC computers base like
Registers and Memory (thanks to Tucker Taft for the VMem like suggestion,
it's almost working).


 Thanks for everyone's help,
Chris Campbell