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MattiMark · 05-25-2015, 07:22 AM

Yesterday I tried to install a HP-41 HP-IL module into my HP-41CX, port 4. In the other ports I had installed a HP-IL Development module, a PPC module and an IR-module.

I had the HP-IL cables loose, not installed to any unit, so when I turned on the calculator it started all right, but when I tried to type a command (CAT 2) it froze. I took out the batteries, but still no response. Trying the batteries in a 41C shows that, alt least, they are ok...

How shall I proceed?

/Matti, Sweden

Hans Brueggemann · 05-25-2015, 08:14 AM

hi matti,
easy fix: set the printer switch on the underside of your HP-IL module to "DISABLE".
always make sure that there is only one printer active at a time on your HP-41. (in your case, you had the IL-Printer ROM "ENABLED" _and_ the IR-Printer installed at the same time. that doesn't work.)

hans

MattiMark · 05-25-2015, 08:45 AM

Hi Hans,

Thanks for the fast reply. I don´t have the calculator at hand right now so I will try it when I get home.

The calculator has 'frozen' - it doesn´t respond to any input nor removal of the batteries. How might that be resolved?

Regards,
Matti

**rprosperi** · 05-25-2015, 01:42 PM

(05-25-2015 08:45 AM)MattiMark Wrote: Hi Hans,

Thanks for the fast reply. I don´t have the calculator at hand right now so I will try it when I get home.

The calculator has 'frozen' - it doesn´t respond to any input nor removal of the batteries. How might that be resolved?

Regards,
Matti

Try resetting, by holding down [ON] and pressing the Back-arrow twice quickly. This procedure is not in the manual, but after learning it long ago (at a PPC meeting probably), I've found it will often restore operation w/o a MEMORY LOST.

TASP · 05-25-2015, 05:52 PM

Appreciate that tip there. I installed an HPIL with the I/R module installed and locked up a machine a while back too. I didn't have anything irreplaceable loaded so wasn't too worried about Memory Lost. The first battery pull or 2 didn't do anything but the third (or forth?) did. Each time I tried it, I left the pack out a little longer. Didn't get a Memory Lost, but was really annoyed with ME for making the error in the first place.

I think there was a module you could make that was described in an old PPC Journal that had a button that would pull an address line lo (or high) or something else entirely, and it would do a soft reset more effectively.

I'm not eager to go looking, but if I do the HPIL-I/R tango again I'd better think about it.

If the 'soft reset' thing looks like a tried and true 'feature', might consider putting it internally in my HP41CX #3 project . . .

Wink

Joe Horn · 05-25-2015, 05:56 PM

(05-25-2015 01:42 PM)rprosperi Wrote: Try resetting, by holding down [ON] and pressing the Back-arrow twice quickly. This procedure is not in the manual, but after learning it long ago (at a PPC meeting probably), I've found it will often restore operation w/o a MEMORY LOST.

Alternative on the 41CX: Tapping ON while holding down the ENTER key performs a system interrupt without erasing memory. Sometimes that's useful for recovering from a bad crash.

MattiMark · 05-25-2015, 06:53 PM

(05-25-2015 05:56 PM)Joe Horn Wrote:
(05-25-2015 01:42 PM)rprosperi Wrote: Try resetting, by holding down [ON] and pressing the Back-arrow twice quickly. This procedure is not in the manual, but after learning it long ago (at a PPC meeting probably), I've found it will often restore operation w/o a MEMORY LOST.

Alternative on the 41CX: Tapping ON while holding down the ENTER key performs a system interrupt without erasing memory. Sometimes that's useful for recovering from a bad crash.

The latter procedure (Joe Horn variant) worked. Once... After turning the 41CX off, well I needed to eventually, it froze again. Sigh.

MattiMark · 05-25-2015, 06:58 PM

Any variant of resetting the 41CX totally? I understand that there is a minimum time when taking out the batteries. Can some one tell me that time?

Regards,
Matti

Sylvain Cote · 05-26-2015, 12:35 AM

Have you tried it without any modules plug-in ?

Les Bell · (This post was last modified: 05-27-2015 08:15 AM by Les Bell.)

(05-25-2015 06:58 PM)MattiMark Wrote: Any variant of resetting the 41CX totally? I understand that there is a minimum time when taking out the batteries. Can some one tell me that time?

I have a recalcitrant 16C that sometimes needs a battery removal reset; I found that it maintained a charge internally for a considerable period of time and it was best to short the battery terminals with a pair of needle-nosed pliers, or the tips of a pair of scissors if the pliers aren't handy. That always brings the beast back from the dead within a few seconds - after the batteries are reinserted, of course.

Given the similarly miserly power consumption of the 41CX, I'd try the same thing.

MattiMark · 05-26-2015, 07:34 AM

(05-26-2015 12:35 AM)Sylvain Cote Wrote: Have you tried it without any modules plug-in ?

Yes, I have removed the modules.

As for the scissors - I will give it a try.

Thank you all for helping me out so far!

/Matti

MattiMark · 05-26-2015, 05:41 PM

The drama continues...

With the help of a pair of scissors and using Joe Horns trick I manage to boot the 41CX. But when I press the ON-button it just freezes. Just that - freezes.

I am no good at syhthetic programming, but I understand that a Memory Lost can be programmed. Can anyone help me with some code? I´d really appreciate that.

/Matti

Dieter · (This post was last modified: 05-26-2015 06:22 PM by Dieter.)

(05-26-2015 05:41 PM)MattiMark Wrote: I am no good at syhthetic programming, but I understand that a Memory Lost can be programmed. Can anyone help me with some code? I´d really appreciate that.

A simple 0 STO c will do.

But can't you just clear memory by the usual procedure, i.e. turn off, and while holding down the backspace key, press ON. Does this work or not?
If pressing ON does not turn the device off, what about a simple one-step program with the OFF command?

Dieter

MattiMark · 05-27-2015, 06:51 AM

(05-26-2015 06:20 PM)Dieter Wrote:
(05-26-2015 05:41 PM)MattiMark Wrote: I am no good at syhthetic programming, but I understand that a Memory Lost can be programmed. Can anyone help me with some code? I´d really appreciate that.

A simple 0 STO c will do.

But can't you just clear memory by the usual procedure, i.e. turn off, and while holding down the backspace key, press ON. Does this work or not?
If pressing ON does not turn the device off, what about a simple one-step program with the OFF command?

Dieter

I cannot force a MEMORY CLEAR by pressing ON and backspace.
I can turn it OFF by pressing ON, but not ON again.

I found this link: http://www.archives.hp41.eu/documents/sav-hp.pdf
I saw that there was an instruction (HP-internal) with some steps where one would press:
ON, ENTER and <--- simultaneously 10-12 times. In the next step there was a CAT 5 test. If that command does not complete one was supposed to send in the 41CX for repair. I am at that stage now.

Does somebody know how to reset the 41CX given the facts at hand?

/Matti

Joe Horn · 05-27-2015, 01:57 PM

(05-27-2015 06:51 AM)MattiMark Wrote: I cannot force a MEMORY CLEAR by pressing ON and backspace.

Just in case it's not obvious, it must be done correctly: Turn off the 41, then press and hold down the backspace key, then press and immediately release the ON key (only once!), then release the backspace key. You should then see MEMORY LOST.

MattiMark · 05-27-2015, 04:53 PM

It worked out just like you stated Joe!

I obviously had not come high enough on the learning curve when it comes to intentional Memory Lost.

I thank you all for the support and time spent on this matter!!!

Best regards,
Matti