Newbie Question re: HP41CX Card Reader


Hi Gang,

Just acquired a HP 41CX (I'm a HP-67 user from way back in the days when it was first introduced). I've loaded in a couple of program tapes from the HP-67/97 Standard Pack and they ran well. Went to load another program and I got the message: "NO ROOM, Try Again." Same message repeats if I load again. I have the X-MEM, STAT and MATH 1 modules plugged into memory slots 1-3 respectively. Is there a command, etc I should run to erase or re-allocate memory, etc? Help please!




Mike, you want the CLP command. Use CAT 1 to list the programs currently in memory, and note an alpha label of you don't want. Now do:


to delete that program from memory.

Alternatively, use stop CAT 1 with R/S when it's on a label of an unwanted program, and do


to clear the current program.


--- Les



Also, you can allocate memory between storage registers and program lines with the SIZE command:

XEQ (alpha)S I Z E(alpha) NNN

Where XEQ is the key to the right of the gold shift key, (alpha) is the alpha key at the extreme upper right, 'S I ' and so forth denotes spelling out the word with the alpha shifted keyboard, without spaces, and NNN are 3 numerals, spelling a number less than or equal to 319, the total number of registers on an HP-41CX.

A 41-CX will come up after a complete "MEMORY LOST" reset with SIZE = 100. That means 100 registers are allocated to data, numbered 0 - 99, and 219 are allocated to program steps. You can tell what your SIZE is on a CX, (or a C or CV with the X Functions module) with the SIZE? command:

XEQ (alpha)S I Z E ?(alpha)

That will return the current SIZE to the X register. If you haven't changed it, it should still be 100. If your programs don't need that many registers, you can choose a smaller SIZE and possibly free up enough to load the extra program.

Of course, with the card reader, you can just load whatever you CLP again later. It does eat batteries though.

Edited: 29 Sept 2005, 11:17 p.m.


Hi Les,

Thanks for your reply. I did as you said.. but, still have problems. I cleared two programs that were shown under the Catalog 1 command. Tried to read a tape afterwards and got the original message "No Room" back again. SST'd through Catalog 1 and got the following: END 121 END 121 .END. REG12 Is this diagnostic in telling you that there is still another step I need to perform? I am trying to understand what you said about memory re-allocation but I'm going to need to do more reading to understand what you were saying to me.




Hi, Mike,

I think the problem is that you are reading HP-67 program cards, which the card reader will translate - but because the 67 had no alpha capabilities, it will simply put a single label in the first line of the translated program: "01 LBL 67".

So there are no alpha labels in memory, and when you run CATALOG 1, it will just show the END statements for each program. If you SST through a CAT 1, and then press R/S, you should then be able to press PRGM, and use SST/BST to get to line 01 of the program. If it's a translated 67 program, you'll see the label I described above. You can then use [XEQ] [ALPHA] C L P [ALPHA] [ALPHA] [ALPHA] to delete the program. You might see the display briefly flash "PACK" after doing this.

You can also get more program memory by executing a SIZE 026, since HP-67 programs, when translated, only use the first 26 registers. Since the default for a 41CX is SIZE 100, this should give you an extra 74 registers' worth of program storage.

Congrats on having a working 41CX and 82104A, btw - the wheel on mine is probably gummy and I've never gotten around to fixing it (one of these days!).


--- Les



Hi Les,

The problem in stepping up to this powerful little calculator (from a HP-67) is that I want to get in and start using it immediately. There is much to learn - and, it must be accomplished "one line at a time."

After following your instructions and executing the CLP command, the problem is fixed. I am likely to assign the CLP command to one of my keys under the USER menu. Looks like I'll be using it quite a bit when running different card programs.

Thanks for all your help and,

Best regards,



Glad it worked, Mike.

I just remembered one other thing: you can avoid the need to keep using CLP by simply positioning the calculator on the previous HP-67 program (rather than after all programs, which would you would do with [GTO] [.] [.]). If the calculator is positioned on a program, then the program you read in will replace that program. See the card reader manual, step 2 at the bottom of page 14, for details.


--- Les



Oh - one more thought: If you want to keep several of those HP-67 programs in memory for frequent use, you might want to insert a short alpha label at the beginning of them, perhaps replacing the "01 LBL 67" that the card reader inserts. Just go into [PRGM] mode, SST to that label, and then press [LBL] [ALPHA] <your text here> [ALPHA]. You will then be able to see your new label in CATALOG 1, making it easier to find the programs you have loaded.


--- Les


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