Changed/supplemented version:

What is VORANOGE?
It is a port of the Voyagers' Pseudorandom Number Generator (built in HP-11C and -15C) to the HP41CX. It could be useful when exactly the same sequence of random numbers is necessary for tests.

What is new in "VORANOGE 3" compared to the first release?
- ROM ID changed from 18 to 13 to avoid interference with Plotter ROM,
- additional function RCLSD recalls currently stored seed (analogous to RCL RAN# available on 15C),
- additional function S21 copies the behaviour of SEED alike HP-21S (only the functionality, not the RAN# generator).
The functions are not sorted alphabetically for CAT2 not to jeopardize programs already written with version 2 of VORANOGE. Those prepared with first version need to be edited due to the ROM ID change.

Warning first
Indispensable prerequisite for this firmware is an HP-41CX either as real machine or running under a so-called "emulator" (one of the CPU-simulating kind). Any former OS of 41C or 41CV will fail, likely to produce a MEMORY LOST or, even worse, alter memory silently. There are no safety measures to prevent you to carry out this misuse.

Intended use
"VORANOGE 3.zip" contains the same 4k ROM in two different formats. The .MOD file may be used with V41 -- https://hp.giesselink.com/v41.htm -- and the .BINJFG may be used with Emu41 -- http://www.jeffcalc.hp41.eu/emu41/index.html See the emulators' description for details how to use application packs.

What else?
This ROM comes with only four commands, SEED, RN, RCLSD, and S21.
SEED stores the content of stack register X to a buffer as sequence start for RN.
S21 does the same but returns also the first pseudorandom number based on the given seed (which itself is copied to LastX).
RN computes a pseudorandom number based on the seed, saves it as new seed and puts it to stack register X.
RCLSD recalls the last pseudorandom number or current seed (what is the same after RN and S21, in contrast SEED might modify the input) or returns 0 if not available.
Notes:
- In case there is no seed when executing RN, some fraction of seconds of current time serve as seed.
- By design the seed buffer is volatile, PACKing or a power cycle (OFF-ON) will flush it. Buffer-ID is 9.

Few more details
For the very first time I prepare a MOD file not on a mainframe under z/VM but on a PC only with mkMOD, a programmer's text editor, and NutEm/PC as emulator. It's doable, it works, alas the details to present are not so detailed as before (in fact, this is a printout from HP41CX):
XROM   FName        Adr.
13.00  -VORANOGE 3  B019
13.01  RN           B11D
13.02  SEED         B10E
13.03  RCLSD        B168
13.04  S21          B0E9

The fine print
"VORANOGE 3" is published under QPL, the Q Public License V 1.0 -- find it also in "VORANOGE 3.zip".
Please read it and proceed only if you do agree.