HHP Portable EPROM


Hello. I just purchased a Handheld Products Portable EPROM reader without a manual. Does anyone have any experience with this device or know where I can obtain a copy of the manual?


Could you send me please a picture ? I have a HHP EPROM Reader for the TI-59...

Thanks and Regards,


This is the version that is enclosed in an HP41 Card Reader housing. It looks just like a card reader except it has "HHP Portable EPROM" listed on the front. It is specifically used for the HP41.



Your HHP Portable Eprom is a 32K Eprom Box.
You can only have 4 size configurations:
4K (one 2764 for L8 & one 2732 for U2)
8K (one 2764 for L8 & one 2732 for U2)
16K (one 27128 for L8 & one 2732 for U2)
32K (one 27256 for L8 and one 2764 for U2)
2732, 2764, 27128 and 27256 are Eproms.
You have 2 DIP switches:
one for memory size & L8 chip type
one for port address
When you open your HHP-PE (remove the 4 screws on HP-41 side), you have something like that:

| ________ |
| | L8 | |
| |________| |
| |
| |1 2 3 4 | |_______
| |
| |1 2 3 4 | |
| ________ |
| | U2 | |
| |________| _______|

The top DIP switch defines the memory size and L8 type of chip used as shown in the table below.
The bottom DIP switch defines the port address desired for the Eprom memory.
SW 1 2 3 4
--- --- --- ---
4K + + + + for 2764
8K - + + or 27128
16K - - +
32K - - - - for 27256

SW 1 2 3 4
--- --- --- ---
port 1 - + + +
port 2 - + - +
port 3 - - + +
port 4 - - - -
SW for switch
+ for up
- for down

To be continued...


I'm assuming the ROM's can be programmed with an image from a Standard HP41 ROM PAC, is that correct? Is there any special format the data needs to be copied to the EPROM before the HP41 recognize it as a standard ROM?



Dear Philipp,
The cheapest tools to copy and convert a ROM into files for Eprom are the following ones:
-HP-Il module,
-disassembling program or ROM (HEPAX DISASM, ZENROM MCED & ENTER for instance)
-IL Interface (GPIO, IL converter, RS232c)
-PC with PROCOMM in order to load the disassembled listing
& GOINTEL (Thanks, Michael Krabach!) in order to translate it into 2 Hex. files for L8 and U2 Eproms.
To be continued...

> Could you send me please a picture ?


Don't anyone tell him that a Clonix module would cost far less and fit entirely in a module slot. :)


it seems that Clonix (and/or MLDL2000 and similar modules) will really shake with EBay prices.


There are two groups of people buying on eBay:

- those who use and enjoy the purchases regularly, as a somewhat nostalgic but valid calculator system. For these people (and I like to include myself here), the Clonix (and the MLDL-2000 in the future) is a godsend, an invaluable addition finally breaking the tiranny of Zeproms and astronomical prices of uncommon equipment

- those who collect the items for collecting's sake, which cause the incredible high prices to occur to begin with, and for whom the Clonix is nothing but a curiosity, not worth much.

Mind you, I'm not passing any value judgements here, everyone's free to do as (s)he wishes, and there's nothing wrong with being a collector - but they sure does screw up the market prices for the rest of us!



Ángel, that depends, if there is a fixed price and a service you can buy it at...
I AM a collector, but I also do not want to bay $200 for a module, when I get the same for $50 in a store....
So, if someone builds me a Clonix module (hardware) I will pay him fair...



Why not paying a lot for something vital or you need absolutely?
For instance I bought a 16K RAM HEPAX module in 1996 (€150).
I though it was crazy but now I have no regret.
It's a stupendous and powerful module for an user like me.
(HP-41 Synthetic Programming & MCode).
I saw this year that some modules reached $400/600.
If price are increasing so much, you have to be patient.
It's not your hour.
In 1994 I read a book about HP-IL (written by Jannick Taillandier).
There was a mention about a Mountain Computer IL Eprom Programmer.
Last year I got one for $75.
I never saw any auction about it but I was ready to put a lot of money.
Now I can directly program my Eprom set from the HP-41 or HP-71B.
I also bought some Gunzen with Zeproms inside.
I had yet a programmer (thanks, Christoph K.!).
I can understand collectors too. Ebay is a market. The higher bidder wins the auction.
However the Clonix module you mentionned is a cheap solution. ;o)


Hi all,

It's still only a spot in my mind but I'm planning to built a 41 modules' reader, to directly dump HP-41 modules (as .ROM images) into a PC.

Hopefully it will need very little hardware (or even no hardware at all) apart from the cable itself.

I'll post the preliminary test results in a few days.

Nice weekend.



Collecting vintage items presents an interesting example of human nature doesn't it. What one thinks is excessive is minimal to another. Just like one man's trash is treasure to another. I'm sure there are many folks that have paid far more for a bottle of wine than I would ever dream to pay, but that is their choice. That is what makes this "game" of collecting fun! I am aware of the Clonix module and yes I'll probably think about purchasing one. Not for its "special" value but because of its functional value (which by the way, for me, would be far less than the HHP module). I know there are many folks that have acquired this same device for far less, but that is the nature of the game. They were in the right place at the right time. I have been in many other "right places" when purchasing other "valuable, collectible" items that I was prepared to pay 10x for. This pyschology is part of our human nature and that is what makes eBay and other forms of trade work. I will continue to admire my extenisve collection of HP items and will continue to pay pennies for other additional items and big bucks other items that move me at the moment.

Thanks for all the feedback.



Maybe the next generation of collectors will pay big bucks for a "rare Clonix module S/N 000002, together with original manual on CD (of course, you need the ancient CD reader for accessing the documentation)" :-)))))

Possibly Related Threads…
Thread Author Replies Views Last Post
  Portable HP Prime Emulator bluesun08 7 2,635 10-03-2013, 01:37 PM
Last Post: fhub
  Programming CMT EPROM modules for HP-41 Paul Berger (Canada) 4 1,903 01-22-2013, 06:04 PM
Last Post: Paul Berger (Canada)
  shelf life time of a ROM, EEPROM, EPROM vs Mask Rom Guido (Canada) 6 2,965 01-11-2013, 04:09 PM
Last Post: Thomas Falk
  Series 80 EPROM cards Paul Berger (Canada) 0 1,153 12-08-2012, 07:50 PM
Last Post: Paul Berger (Canada)
  HP-41 CMT EPROM & ZEPROM Programming Dan Grelinger 3 1,465 11-26-2012, 02:42 AM
Last Post: Diego Diaz
  CMT EPROM Info Sought Namir 5 2,154 05-18-2012, 03:34 AM
Last Post: Namir
  Need a US proxy for a battery for an HP Portable Plus Geir Isene 5 1,925 10-31-2011, 07:56 PM
Last Post: John Pierce
  Anyone know anything about this HP41C RAM / EPROM ROM SIMULATOR? Bruce Larrabee 11 3,101 09-30-2011, 02:25 PM
Last Post: Ángel Martin
  HHP-16K EPROMS on HHP PE Prabhu Bhooplapur 0 779 07-23-2011, 07:47 AM
Last Post: Prabhu Bhooplapur
  HP-75 EPROM programmer Jeff Davis 10 2,439 04-01-2011, 12:01 PM
Last Post: Jim Horn

Forum Jump: