Post Reply 
HP-41CL & NOV modules
02-02-2018, 12:53 PM (This post was last modified: 02-02-2018 12:54 PM by Geir Isene.)
Post: #1
HP-41CL & NOV modules
I miss the permanency of the NOV HEPAX storage.

Whenever I wrote something to NOV HEPAX RAM, it was safe. If the calculator locked up, crashed or batteries had to be removed to restart it, anything I had saved to HEPAX RAM was safely kept in the NOV module.

With the HP-41CL, HEPAX is kept in RAM and the RAM has to be written to flash manually at intervals - and it does take a bit of time. And if I didn't yet write those HEPAX RAM pages to flash before the calc went dead, my changes were gone.

So, I would perhaps want to use my NOV-64 on my HP-41CL to get the best of both worlds. But this has proved quite unstable. NOV-64 relies on the address 4100 and I have LIB4 in page 4... and as I am relying on lots of HP-IL stuff, locating YFNZ/X in page 7 is a no-go... it has to go somewhere in pages 8-F. But that space is taken over by the NOV-64 and I've had odd conflicts there.

Any thoughts on how to make a really good setup with both the HP-41CL and NOV modules without excluding LIB4?
Find all posts by this user
Quote this message in a reply
02-02-2018, 02:09 PM
Post: #2
RE: HP-41CL & NOV modules
(02-02-2018 12:53 PM)Geir Isene Wrote:  Any thoughts on how to make a really good setup with both the HP-41CL and NOV modules without excluding LIB4?

First, address 0x4100 in the Library#4 is left free - precisely for this reason - so it's compatible with NOVO settings.

I've used mine a few times on the CL without any stability problems, just the opposite.
I typically plug YFNX in page#7 though, so there's no conflicts/

The only consideration is that being a physical external module (not in CL flash or RAM) the execution speed is kept at 1x regardless of the TURBO setting.

Cheers,
ÁM
Find all posts by this user
Quote this message in a reply
02-02-2018, 02:17 PM
Post: #3
RE: HP-41CL & NOV modules
(02-02-2018 02:09 PM)Ángel Martin Wrote:  
(02-02-2018 12:53 PM)Geir Isene Wrote:  Any thoughts on how to make a really good setup with both the HP-41CL and NOV modules without excluding LIB4?

First, address 0x4100 in the Library#4 is left free - precisely for this reason - so it's compatible with NOVO settings.

Good to know.

(02-02-2018 02:09 PM)Ángel Martin Wrote:  I've used mine a few times on the CL without any stability problems, just the opposite.
I typically plug YFNX in page#7 though, so there's no conflicts/

And here is perhaps my main issue then - page 7... which I need for HP-IL. I remember vaguely that Diego's module can have some sort of "shadow mode" where anything else plugged into a page will have priority and that this NOV page will be put in the background... or something.

(02-02-2018 02:09 PM)Ángel Martin Wrote:  The only consideration is that being a physical external module (not in CL flash or RAM) the execution speed is kept at 1x regardless of the TURBO setting.

That's a bummer. Is there any way to make it run in Turbo50, or would that wreck the NOV write code?
Find all posts by this user
Quote this message in a reply
02-07-2018, 05:11 PM
Post: #4
RE: HP-41CL & NOV modules
As an answer to your question about the No-V running in Turbo mode in the HP-41CL. I have multiples of both products. When the 41CL is running in Turbo mode (2 - 50), the only instructions that are executed at increased speed are those that operate only in the 41CL circuit board. The modern components of the board, processors and memory, are capable of running at a very fast speed. When interactions are required with other components (HP-41C display, keyboard, things connected to the I/O port like the No-V modules) the 41CL circuit board manages those interactions at the original HP-41C bus speed, which slows things down quite a bit, even when the 41CL is running internally at turbo speed. And in my original work years ago with the NoV modules, I found that they were not capable of running very much faster than the standard -41C bus speed.

To the HP-41C, the NoV is just a memory device (even though it is quite intelligent inside). When the 41-CL is operating in Turbo mode, it slows down to address and accept data from a module plugged into a I/O port. That happens at 1X speed, but when the commands obtained from the module are executed in the 41CL board, they are executed at turbo speed. The result is a speed improvement, but not the full speed improvement expected (e.g. 50X will not be achieved when running in Turbo50 mode and running programs in the No-V module).
Find all posts by this user
Quote this message in a reply
02-08-2018, 03:49 PM
Post: #5
RE: HP-41CL & NOV modules
Thanks for the insight.
Find all posts by this user
Quote this message in a reply
Post Reply 




User(s) browsing this thread: 1 Guest(s)