HP-41CL & NoV(-64): Race condition?



#13

I have on several occasions noticed that the MMU on the 41CL has been reset upon turning the calc on when I have a NoV-64 plugged in.

Sometimes the time has also been reset.

This does not occur when I do not have the NoV module plugged in.

I suspect a race condition.


#14

I assume that you mean the the MMU has been disabled. This will happen if the POR (power-on-reset) function on the CL board detects that the supply voltage has dropped below a certain value, even if transiently. The Time Module has a similar function built-in, although it operates off of a different supply. The one on the CL board itself monitors the 3.3V supply for the RAM and CPLD. I think that the only way that the POR(s) can be triggered is if the supply dips because of a surge in current drawn while the CL (and NoV-64) is powering up. Since it is affecting both the CL board and the Time module, this suggests to me that the problem is with the I/O block that connects the battery pack to the main board. If this current path is not able to carry the power-up current surge the voltages at the PORs might dip enough to trigger them. So I would check for corrosion/oxidation on the I/O block connections to the battery and the main board.

Monte


#15

Monte; It is regardless of corrosion (both my CLs does this - and only when the NoV is plugged in. Could it be that since the NoV requires juice, the CL will detect a lack of juice abd disable the MMU?


#16

It may be that there is a current surge on power-up from the NoV that is sufficient to cause the voltage to droop enough to trigger the POR. I suppose that there could also be a transient bus fight between the CL board and the NoV, but the 41CL is designed to force all drivers off until it actually comes out of reset, so I consider this to be unlikely. Does it happen less frequently with new batteries? I am not familiar enough with the NoV design to talk about what kind of current surge there might be.


#17

I have not really noticed any difference with new batteries...

#18

I'm really wandering if there is anyone in this world to use the HP-41 for real work. I use it as a number cruncher because of nostalgia.


#19

Isn't nostalgia real work?

Consider the HP-41 as a Glass Bead Game . Then Ángel Martin should be treated as "Magister Ludi".



Cheers

Frido


#20

Quote:
Then Ángel Martin should be treated as "Magister Ludi".

That'd be an honor (Hesse, no less!), and certainly gentler than "The Last Mohican" - though I needn't say that's not true, just check the "What's New" section at TOS to see.

Cheers, ÁM

#21

Quote:
I'm really wandering [sic] if there is anyone in this world to use the HP-41 for real work.
This comes up from time to time. Yes, I use my 41cx every day, because it is functional, not because of any nostalgic value.

#22

Of course I use HP41 system - and now the more powerfully and much faster 41CL for real world applications : More in detail - I run hardware interfacing and measurement applications with I/O-Board and IL2000 Interface System, which means HP-IL is included to my applications :-)

Best regards - Christoph

#23

Quote:

This comes up from time to time. Yes, I use my 41cx every day, because it is functional, not because of any nostalgic value.


I second that. Twice.

#24

Hi Geir, all,

Late as usual but I'd like to help.

Can you please, mail me with details so I can try to replicate the problem.

Thanks and best wishes.

Diego.


Possibly Related Threads...
Thread Author Replies Views Last Post
  HP-41CL setup troubleshooting Xavier A. (Brazil) 2 236 12-02-2013, 06:29 AM
Last Post: Xavier A. (Brazil)
  HP-41 Clonix&NoV's SW Update. (For the non-Primer's guys out there... :-) Diego Diaz 21 700 11-13-2013, 09:00 AM
Last Post: Ángel Martin
  [41CL] New Extra Functions version Monte Dalrymple 0 142 11-08-2013, 04:32 PM
Last Post: Monte Dalrymple
  The worst condition 15C? Keith Midson 8 381 10-16-2013, 10:41 AM
Last Post: walter b
  So, latest 41CL / Library 4 config is... Gene Wright 4 284 09-22-2013, 02:59 AM
Last Post: Ángel Martin
  HP-41CL anyone? Matt Agajanian 8 355 08-31-2013, 12:27 AM
Last Post: Sylvain Cote
  [41CL] A couple more rhetorical questions Monte Dalrymple 1 154 07-12-2013, 09:28 AM
Last Post: Ángel Martin
  41CL :TROUBLE IN FILE TRANsFER aurelio 22 890 06-18-2013, 03:44 PM
Last Post: aurelio
  [41CL] Another question for users Monte Dalrymple 28 1,065 06-03-2013, 10:04 AM
Last Post: Geir Isene
  [41CL] Updated Manual Monte Dalrymple 1 141 05-14-2013, 10:22 PM
Last Post: Matt Kernal

Forum Jump: