YouTube demonstration of the 41CL


This video demonstrates for the beta testers the use of the simple routine "YCTOF" which was sent to them via a PDF. I you would like a copy email me.

This also for any die-hard HP 41C fan as it demonstrates a fantastic option available to the CL user. The ability to copy many calculator-states to the FLASH memory where it resides impervious to MEMORY LOST states or power interupts.

In fact, lets say you use the Blood Glucose monitor XROM. This XROM takes over the calculator at turn on. Reserves 100 storage registers and reassigns the entire keyboard. It actually turns the 41C into a dedicated Blood Glucose monitor to the exclusion of all other routines.

The CL will allow you to record your Blood Glucose data and the store the entire calculator state to FLASH. Once there, another state can be recalled to the calculator memory.

In my case, I record lab data to a calculator state which has a suite of Palynology Climate routines. Then when I go to work, I copy the Palynology state to the CL board and recall my aviation suite of programs from the FLASH.

Enjoy the video (my second youtube adventure)

The use of the "YCTOF" routine and a short plug unplug routine at the end...

Cheers, Geoff


using the module HEPAX to restore the entire contents of the hp just use 'HGETA'.


A little more explanation please ;-)

I am not familiar with HEPAX although I intend to be. Do you store the contents to a specific location and then when prompted, supply the location.

Can the function store to more then one location? Does it store X-memory contents also?

Cheers, Geoff


Ah! I see, HEPAX is fantastic:


But this works with a physical HEPAX module only? If so can the virtual HEPAX module contained in the CL be used to store to multiple locations on the CL of many calculator states. Does the HEPAX module have more then one 4K location for the storage of the calculator states.

Questions and more questions. Also, how long does the entire transfer to the safe memory location work. 22 seconds on the CL becomes minutes without TURBO50 initiated.

Cheers, Geoff


The CL can run Hepax and it will be as if you have a Hepax installed.

However, I believe the Hepax "save the calculator state" functions save them to memory within the Hepax structure itself - at the expense of having one of the 41CL port locations hold the Hepax module as well as the space for the saved files.

Probably two port locations used.

And, finally (ha), the Hepax memory locations are probably mapped to RAM locations within the 41CL structure, which would not survive a total power loss the way your approach of copying to the calculator state to flash.

Don't think Hepax can be running on the 41CL with the Hepax memory mapped to flash.


Thanks Gene for the explanation. I was thinking along the same lines, plus not many states can be stored as in the CL.

The CL can do the following:

save the data collected on the a survey to the flash (acting as a survey dedicated computer).

recall the aviation calculator state to fly out of the survey zone acting as a flight computer.

swap that state with the Palynology lab data I have turning the it into an Palynology computer.

swap and recall the data loaded into the Blood Glucose monitor (acting as a Blood Glucose dedicated monitor) for that days intake, swap that back to FLASH and recall whatever else you have loaded.

So the above hypothetical example has created 4 devices in one without the need of a physical module or the other mass storage HPIL, RS232 connections required by other systems. Also as you stated, protected from prolonged power interupts... In fact, you can swap the CL board out of a damaged shell and into a spare shell and all the data goes with it.

Cheers, Geoff


HEPAX RAM is mapped to the ROM ports of the 41 address bus. The CL has a whole different memory structure, and only part of it is addressed to the 41. So you could have different SETS of HEPAX RAM stored into either CL flash or CL-RAM, ans swap them at will using MMU commands.

Gene's right for the HEPAX to work it has to be in CL-RAM, otherwise the WROM instruction wouldn't work.

What the HEPAX HGETA/HWRTA functions will do for you is a convenient write all / read all. That combined with the MMU y-functions makes an unprecedented control and versatility - way beyond the CY, or even the ML2k - although the ML2k has the incredible advantage of being all PC-controlled using the USB bus.



Slightly OT, because CY not CL:

Restoring a W&W 41 CY (2x 32K) from my special CY-INIT ROM takes ~70 seconds with normal speed (speedup not active).

This includes:

- storing RAMBOX64a and -b

- my CCD OS/X

- David Assembler

- my Ext IL+

- Mainframe Labels

- clearing the remaining pages A,C,E

The above actions are performed twice, once for each of the two banks.

So copying 10 pages takes ~50 seconds, and clearing 6 pages takes ~20 seconds.

Not very fast compared to a CL, but still not bad for a device with age ~25 years;-)



Geoff, I have long used J&J One Touch meters as they have free software to use in a PC to download, store and display your readings. It is fairly common now as other makers followed. I use the "standard day" presentation and the serial reading presentation. Moving the cursor onto a displayed reading will show the date and time and value.
Regards, sam

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