NoV-64D and HEPAX Questions

[Sylvain Cote]

Mike,

I understand.

(04-04-2024 03:18 PM)BitWiz Wrote:  Here's what I understand the NoV-64D can do:
1. NoV-64D 48K flash ROM - Map any 4K block of flash ROM to any HP-41 Page and Bank.
2. Nov-64D 64K FRAM - Map "RAM Chip" 1, 2 or 3 (16K) to HP-41 Pages 0x8 to 0xB.
3. Nod-64D 64K FRAM - Disable flash ROM and MAP, "RAM Chip" 1, 2 or 3 (16K) to HP-41 Pages 0xC to 0xF.

Yep! that is almost correct.
1. NoV-64D 48K flash ROM - yes, but the first 4 pages (0 to 3) are not supported. It means that you cannot replace the 41OS.
2. Nov-64D 64K FRAM - Map "RAM Chip" 0, 1, 2 or 3 (16K) to HP-41 Pages 0x8 to 0xB.
3. Nod-64D 64K FRAM - nothing to add

(04-04-2024 03:18 PM)BitWiz Wrote:  1. Can the HEPAX RAM (regardless of what RAM chip it is) be assigned in 4K blocks to any HP-41 Page and Bank like the NOV-64D flash ROM?

The NoV modules are not pure MLDL boxes, they are HEPAX emulators and behaves as such. So, no QROM page reassignement and no bank support.

(04-04-2024 03:18 PM)BitWiz Wrote:  2. Clonixconfig puts the HEPAX ROM at HP-41 Page 8. However, the NoV-64D configuration, in both 16K and 32K mode puts RAM there. If all HP-41 Pages below 8 are in use (library 4 in HP-41 Page 4, HP-IL module installed). Will the HEPAX module see that HP-41 Pages 0x8 - 0xB are RAM and then move itself to HP-41 Page 0xC?

The NoV-64 module behave exactly like the original Advanced HEPAX (ROM:16K+RAM:16K) and the Double HEPAX (RAM:16K) memory modules were behaving.
With the original Advanced HEPAX module, when inserted in port 1 or 2, at power up ROM, the ROM is being mapped to page 8 and the HEPAX RAM is also mapped to page 8, then the 41OS calls the HEPAX ROM power-up polling point routine which then scan the pages from 5 to 15 to find an empty page (no ROM or QROM), if it find one, it then remapped his own ROM to that page and thus preventing a page lockup.
Ex#1: 41CV + Adv HEPAX -> the HEPAX ROM will be relocated from page 8 to page 5
Ex#2: 41CV + Adv HEPAX + Time -> the HEPAX ROM will be relocated from page 8 to page 6
Ex#3: 41CV + Adv HEPAX + Time module + HP-IL module -> the HEPAX ROM will be relocated from page 8 to page C

(04-04-2024 03:18 PM)BitWiz Wrote:  3. The NoV-64D can assign HEPAX 16K RAM chips 1, 2 & 3 but there are 4 16K RAM chips in the NoV-64d. How does that last 16K get used.

See my correction above, HEPAX 16K RAM chips 0 is the default one.

(04-04-2024 03:18 PM)BitWiz Wrote:  4. In conjunction with the answer to #1, how do I assign HEPAX RAM as QROM 4K blocks to HP-41 Page and Bank?

You cannot.

(04-04-2024 03:18 PM)BitWiz Wrote:  5. Are there HEPAX ROM commands that will allow me to reconfigure the HEPAX RAM (as QROM) mapping in the HP-41 M-Code address space so that I can enable and disable QROMs (with a power cycle) under software or manual control without having to download new ROM images into the HEPAX RAM? This would allow me, for example, to turn on the PPC ROM when I want to use it but map that out and map the HP-IL DEV ROM into the same 2 HP-41 Pages?

Nop!

(04-04-2024 03:18 PM)BitWiz Wrote:  6. Will #5 work with bank selected ROM in QROM.

Nop!

It is clear to me that you have the wrong module for what you are trying to do.

The NoV-64 module goal is to emulate the Advanced HEPAX and the Double HEPAX memory modules, period.
In this role, it is the best HEPAX implementation that I have seen to date.
You also have some supplemental features, but these are icing to the cake.

The MLDL2000 was a better fit for what you are trying to do, unfortunately it is no longer produced.

The upcoming MAXX module should be able to do what you want.
MAXX Module feature summary from Monte Dalrymple (MAXX module manual)

• 1x 4K 10-bit MAXX ROM.
• 4x 82106A memory modules, if missing.
• 1x 82180A X-Functions/Memory module, if missing.
• 2x 82181A X-Memory modules, if missing.
• 1x 82182A Time module, if missing.
• 3x 1024 56-bit SRAM Y-Memory registers.
• 12x 4K 10-bit SRAM bank capable QROM pages.
  
  • can hold HEPAX ROM images and HEPAX RAM pages
  • can hold RAMBOX ROM image and QROM pages
  • etc
    

Also, there is another module being developped that could do what you want.
See: HP41C with Rp Pico attached and HP41 with Pico RP2040 attached, update

And, if you have a fullnut calculator, the 41CL motherboard replacement is able to do what you want.

(04-04-2024 03:18 PM)BitWiz Wrote:  If this still doesn't make clear what I am trying to accomplish, please DM me
and I will send you my phone number and maybe we can clear all of this up in a quick phone call.

You have a PM.

Sylvain