Checking how much memory I have on HP-41CV

[CheshireChris]

I know nothing about HP calculators (a situation which I hope will soon change!) and have just bought my first one, an HP-41CV in really good condition. It has an "X FUNCTIONS" and two "X MEMORY" modules plugged in which, as I understand it, should give it its maximum possible memory configuration. I'm going to start reading manuals shortly, but is there any quick command I can use to check that all the memory that should be there actually is there? Ie, that all three modules are correctly being detected?

Thanks,

[Sylvain Cote]

(08-13-2024 01:27 PM)CheshireChris Wrote:  I know nothing about HP calculators (a situation which I hope will soon change!) and have just bought my first one, an HP-41CV in really good condition. It has an "X FUNCTIONS" and two "X MEMORY" modules plugged in which, as I understand it, should give it its maximum possible memory configuration. I'm going to start reading manuals shortly, but is there any quick command I can use to check that all the memory that should be there actually is there? Ie, that all three modules are correctly being detected?

Thanks,

1. HP 82180A Extended Functions Memory Module Owner's Manual (aka XFM)
2. HP 82181A Extended Memory Module Multilingual Instructions (aka XM)
   

XFM manual (1), p.23, EMDIR

If X-Memory is empty, EMDIR will show "DIR EMPTY" and X contains the number of usable x-memory registers left.

X=124 with XFM only
X=362 with XFM + XM
X=600 with XFM + XM + XM

Look at XM instructions (2), P.15, for how to install XM modules.

Sylvain

[emefff]

Hello!

With all three modules plugged in, "XEQ ALPHA EMDIR ALPHA" should give the result "DIR EMPTY" and upon pressing another button will show the free registers "600".
Anything less probably points to a X-MEMORY module with bad contact or another problem. Every X-MEMORY will add 238 registers. The X-FUNCTION module will have 124 registers. EMDIR is a command located in the X-functions module, so it will not work without it. It would show "NONEXISTENT".

Hope that helps,

Mario.

[CheshireChris]

Thank you both - that's very helpful. Yes, I get first "DIR EMPTY" and then "600", so it looks as if all is as it should be. I just wanted to check so I could let the seller know if there was a problem.

I've started working my way through the User Guide now!

[Garth Wilson]

EMROOM will also tell you how much free extended-memory registers are free.  And again, each register is 7 bytes.

[cdmackay]

Also, Catalog 4 will show you all files in EM (if any) with their type and allocated size, in order of creation, and end with the number of free registers (EMROOM).

[Garth Wilson]

(08-13-2024 09:06 PM)cdmackay Wrote:  Also, Catalog 4 will show you all files in EM (if any) with their type and allocated size, in order of creation, and end with the number of free registers (EMROOM).

I think the cv requires EMDIR, not having CAT 4 like the cx has.  Is that correct?

[rprosperi]

(08-13-2024 09:12 PM)Garth Wilson Wrote:  

(08-13-2024 09:06 PM)cdmackay Wrote:  Also, Catalog 4 will show you all files in EM (if any) with their type and allocated size, in order of creation, and end with the number of free registers (EMROOM).

I think the cv requires EMDIR, not having CAT 4 like the cx has.  Is that correct?

Yes, correct. The CV with Ext-Func/Mem includes the EMDIR command, but the integrated CAT-4 (as well as -5 and -6) and EMROOM are NOT available in a 41CV.

[cdmackay]

Sorry! I only have a 41CL which behaves (in this regard) like a fully populated CX.

[rprosperi]

(08-14-2024 12:01 PM)cdmackay Wrote:  Sorry! I only have a 41CL which behaves (in this regard) like a fully populated CX.

As limitations go, you've got a fairly good one. Only having a 41CL is a problem many readers wish they had... lol.

[cdmackay]

Quite right Bob; I should have said I'm extremely fortunate to have Monte's excellent 41CL

[CheshireChris]

(08-14-2024 12:09 PM)rprosperi Wrote:  As limitations go, you've got a fairly good one. Only having a 41CL is a problem many readers wish they had... lol.

I now also have a DM41X, so I too can use 41CX commands!

[rprosperi]

(08-15-2024 10:11 PM)CheshireChris Wrote:  

(08-14-2024 12:09 PM)rprosperi Wrote:  As limitations go, you've got a fairly good one. Only having a 41CL is a problem many readers wish they had... lol.

I now also have a DM41X, so I too can use 41CX commands!

Welcome to the club, I think you'll enjoy learning and using the 41X, the extensions make exploring many of the more exotic aspects of 41 play a lot easier. Once you're used to it, please consider leaving feedback and comments. Have fun!