Quick HP42S question

[Joe Horn]

The following comment section in HP's original source code for the HP 48 series gives further support to the random number generator's period being 5E13 long if the seed ends in 1, 3, 7, or 9, which the RDZ code automatically does.

Code:

        STITLE    %RANDOMIZE
*****************************************************************
**
** Name: %RANDOMIZE
**
** Abstract: Updates [RNSEED] by user input (% <> 0) or by
**           the system clock (% = 0).
**
** Stack: % -->
**
** Exceptions: none
**
** Author: All inquiries may be addressed to the late great
**         Homer Russel, wherever he is.
**
** Algorithm:
**
**  x(n+1) = a * x(n) + c  (mod m)
**
**  here: a = 2851130928467  [= 67 (mod 200)]
**        c = 0
**        m = 10^15
**
**  If x(0) # 0  (mod 2) and x(0) # 0 (mod 5) then the period
**  is 5*10^13 (Theorem D, pg. 19 of Knuth Vol. 2).
**
***Date Changed      Programmer            Reason
***------------      ----------      -------------------
**  1/15/86         P. McClellan           packed
** 08/24/89         SB             BugFix: Use SysTime (Not TIME)
*****************************************************************