Hi, Kevin;
I also own a NoVRAM and a NoV32, and the main difference is 'USER' memory, if I can say so.
Either a NoVRAM or a NoV32 can be configured to work as a Clonix. A NoV32 can also be configured as a NoVRAM. The Clonix itself has a 512bytes available RAM that can be accessed through specific commands, available with HEPAX, David Assembly, etc. 512 bytes is 1/8 the maximum capacity that can be addressed in each HP41 page, meaning each page can access up to 4KRAM or 4KROM. The NoVRAM has 16KRAM (nonvolatile) organized in 4 pages, and the NoV32 has 32KRAM (also nonvolatile) currently organized in two blocks of 4 pages each. Any of these modules allow a separate configuration of 6 x 4KROM pages (up to 6 ROM images in FLASH ROM), so you can find your own combination. The best one I found so far was HEPAX (4 pages of 4KROM each) + two 4KROM + 4 x 4KRAM. In time: the HP41 internal addressing allows each 4KRAM/ROM to be organized in 'banks', up to four banks each. So, the virtual total address an HP41 can access is 4 x 16 x 4KRAM/ROM, considering each possible page. In fact, system ROM occupies the lowermost 3 pages (P0, P1 and P2) and the remaing 5 pages (P3 to P7) are used for special purposes, mainly system ROM extensions (Timer ROM, Extended Functions ROM, printer ROM, HPIL ROM, etc, etc...). HEPAX can be addressed to at least two of these 'system addressed' pages, namely P5 or P7, but neither the HPIL (P7) nor the X-Functions (P5) should be used in this case, thought. Pages 8 to F are used the way you wish, being each two pages initially addressed to each of the four ports in the back of the calculator.
This is what I can briefly write by heart, should read some existing material to go ahead. Hope this helps so far.
Cheers and welcome to the HP41 internals...
Luiz (Brazil)
Edited: 14 Sept 2006, 4:53 p.m.