HP Forums
New module ISOKINETIC - Printable Version

+- HP Forums (https://www.hpmuseum.org/forum)
+-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html)
+--- Forum: General Forum (/forum-4.html)
+--- Thread: New module ISOKINETIC (/thread-17609.html)

New module ISOKINETIC - abalasa - 10-22-2021 08:58 PM

I have a module I know nothing about. On it there is a label "8k", I assume this means 8K PROM or EPROM inside (didn't take it apart) and the CAT gives the following function list (see image attached).

Anyone knows anything about the module?

Thank you

RE: New module ISOKINETIC - abalasa - 10-22-2021 09:03 PM

Well I do not seem to be able to post an image, here is a share from a Google drive


RE: New module ISOKINETIC - mfleming - 10-23-2021 01:39 AM

It would certainly help to mention which calculator the module is meant for. HP-41? HP-71B? The CAT listing doesn't look like either, but I'm certainly not any sort of expert Smile

RE: New module ISOKINETIC - abalasa - 10-23-2021 02:02 AM

You are of course right. It is a HP-41 module. The CAT listing was obtained from a HP-41C with IR interface and a 82140a printer, the actual command was CAT 2. I cut from the printout the printer commands. The module does not seem to work unless it is in port 3, in port 1 the calculator hangs with the module inserted.

RE: New module ISOKINETIC - rprosperi - 10-23-2021 03:45 AM

(10-23-2021 02:02 AM)abalasa Wrote:  The module does not seem to work unless it is in port 3, in port 1 the calculator hangs with the module inserted.

Assuming the 41 you're using has known good ports, a module only working in some and hanging in port-1 probably means it is part of an application that requires multiple modules, which in this case probably need to be port-1, or possibly in port-1 and -2. Did this module come with any others?

Isokinetic means constant-speed, and the other routine names suggest this is used for some kind of mass- or fluid-transfer calculations; the "Meth N" routines are likely different methods of treating the material being transported thru some process.

Either that or it's a recipe book for a meth lab, which seems unlikely.

RE: New module ISOKINETIC - abalasa - 10-23-2021 11:19 AM

The calculator had 4 modules, 3 memory (82106) and this. The 3 82106 seem to be just that, memory modules. One port (4) on that machine does not seem to be operational but ports 1 and 3 are, tested with other modules. However the "hanging" operation may or may not be related, while testing other modules I got frequently "memory lost" while inserting stuff in port 3 (all modules were swapped only with the machine off) so there is definitely something afoot here not related to the Isokinetic pac. Apart from that, the calculator is one of the first 41Cs made in USA 1980.

RE: New module ISOKINETIC - mfleming - 10-23-2021 12:09 PM

Module contact problems in some ports and not others is usually due to corrosion or deteriorating upper posts. Lack of company or application markings on the module shell definitely suggest a low volume custom application. The routines are most likely user RPL, so your next step could be to list them out for analysis. The single letter labels are possibly variables in an equation.

Congrats on acquiring an early model!

RE: New module ISOKINETIC - Bill (Smithville NJ) - 10-23-2021 12:12 PM

From the module cat listing, I'm thinking it might be a module for sampling stationary source emissions for pollutants in accordance with US EPA Reference Methods. See the following links:

Isokinetic Sampling

Isokinetic Flow Calculator

An interesting module. I'm always surprised at how many different specialized modules were developed for the HP-41.

Smithville, NJ

RE: New module ISOKINETIC - Diego Diaz - 10-23-2021 02:43 PM

Hi all,

A picture of the module itself would be very helpful too.

However, since it has an "8K" label, my first guess would be that this is a CMT EPROM module loaded with a set of FOCAL programs for Isokinetic specialized applicaton.

The most evident difference between HP modules and CMT's is that the latter don't have a retractable pulling handle. They also have two small open slots on their sides.

You can also get a hardcopy of the programs; that will help to find out the real usage it was intended for.

Interesting finding anyhow. :-)

Best wishes.


RE: New module ISOKINETIC - abalasa - 10-23-2021 03:07 PM

Here is a link to an album with some images. Indeed the handle is not retractable and there are two slots on the sides, one each side. If this is indeed an Eprom with a custom application I doubt we will find any real documentation. Question: could this be reprogrammed, and if yes, would it be of any use? I see many "desirable" but rare ROMs are 8k or less.


I am not able myself to dump the code inside, if anyone wishes to do so to document it or archive it, let me know directly please.

RE: New module ISOKINETIC - Diego Diaz - 10-23-2021 04:59 PM


And thanks for the images link.

This confirms it is a CMT EPROM module.

Regrettably these modules can only be reprogrammed with a dedicated fixture which is "unobtanium" and after erasing it with an UV ligth. Not quite convenient for today standards. :-(

In order to list the programs just use the printer command "PRP" then [ALPHA] and enter the name of the program as listed in your CAT 2 output. It is indeed a long task and don't know if there's enough interest but chances are that this is the only module of its kind.

Best wishes.