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HP41 extension ports pinout
02-11-2019, 02:01 PM
Post: #1
HP41 extension ports pinout
Hi!

I was wondering if there is a place with all the details about the expansion ports? It would be very easy to write new expansion cards using an arduino chip, or a $3 USD ESP8266 to give the 41 access to wifi

Can anyone point me in the right direction?

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02-11-2019, 06:28 PM
Post: #2
Try the service manual?
I'm no expert on this, but maybe the HP 41C/CV/CX Service Manual will be helpful.

http://www.decadecounter.com/vta/pdf/HP%...-90472.pdf
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02-11-2019, 07:18 PM
Post: #3
RE: HP41 extension ports pinout
(02-11-2019 02:01 PM)eried Wrote:  ...or a $3 USD ESP8266 to give the 41 access to wifi

In any case I doubt easy is accurate, but it's worth pointing out that the 41C does not have a TCP/IP stack, so even if WiFi h/w was available, (including the equivalent of a driver in MCODE) you still could not do much with it, or maybe you have more ambitious goals in mind. Not trying to rain on your parade, just want to make sure you know how much you are tackling.

--Bob Prosperi
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02-11-2019, 07:27 PM
Post: #4
RE: HP41 extension ports pinout
My immediate idea was this
http://www.hpmuseum.org/guest/klug/dblxmem.pdf
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02-11-2019, 08:51 PM
Post: #5
RE: HP41 extension ports pinout
(02-11-2019 07:18 PM)rprosperi Wrote:  
(02-11-2019 02:01 PM)eried Wrote:  ...or a $3 USD ESP8266 to give the 41 access to wifi

In any case I doubt easy is accurate, but it's worth pointing out that the 41C does not have a TCP/IP stack, so even if WiFi h/w was available, (including the equivalent of a driver in MCODE) you still could not do much with it, or maybe you have more ambitious goals in mind. Not trying to rain on your parade, just want to make sure you know how much you are tackling.

Yes, I am aware, and probably no calculator has a tcp/ip stack. However I am just thinking on some super simplified interface where the ESP8266 handles everything. Imagine for example just copying a program in your PC transferred it to the calc like if you swiped a magnetic card on it

Checking the prices for the modules and accessories for the 41 made me think it is a way better investment to research into doing something new Smile

(02-11-2019 07:27 PM)AndiGer Wrote:  My immediate idea was this
http://www.hpmuseum.org/guest/klug/dblxmem.pdf

Thanks for the links! this is specially useful

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02-11-2019, 09:21 PM (This post was last modified: 02-11-2019 09:21 PM by CY-CL.)
Post: #6
RE: HP41 extension ports pinout
The NUTIP Module installs a TCP/IP stack in your HP41. You can configure an IP and setup the 41 as webserver and list programm’s on your web browser . The communication from HP41 goes over the RS232 interface.

Have fun!
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02-11-2019, 09:21 PM
Post: #7
RE: HP41 extension ports pinout
(02-11-2019 07:18 PM)rprosperi Wrote:  
(02-11-2019 02:01 PM)eried Wrote:  ...or a $3 USD ESP8266 to give the 41 access to wifi

In any case I doubt easy is accurate, but it's worth pointing out that the 41C does not have a TCP/IP stack, so even if WiFi h/w was available, (including the equivalent of a driver in MCODE) you still could not do much with it, or maybe you have more ambitious goals in mind. Not trying to rain on your parade, just want to make sure you know how much you are tackling.

I think you can talk to it with AT commands to set up a connection. No TCP/IP stack required in the calculator.

— Ian Abbott
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02-11-2019, 10:52 PM
Post: #8
RE: HP41 extension ports pinout
(02-11-2019 08:51 PM)eried Wrote:  ...However I am just thinking on some super simplified interface where the ESP8266 handles everything. Imagine for example just copying a program in your PC transferred it to the calc like if you swiped a magnetic card on it

I see, wow that's aggressive, but it would simplify things on the device side. Perhaps the easiest approach is to somehow emulate (or use existent) 41 Extended memory in your new device that plugs into the port so that normal functions in the 41 can store and read programs and data. To be clear, by "easy" I mean easiest on the 41 side of things, where essentially no (or very minimal) software would be needed, but it still could exchange programs and data registers. Otherwise, you'll have to also write the 41-side MCODE for moving the data in and out.

Monte Dalrymple, creator of the 41CL, announced early work on a general purpose I/O board for 41 ports at HHC2018; you should check that out as it may be helpful as a kind of "middle-ware" for your planned device.

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02-11-2019, 11:21 PM
Post: #9
RE: HP41 extension ports pinout
(02-11-2019 10:52 PM)rprosperi Wrote:  
(02-11-2019 08:51 PM)eried Wrote:  ...However I am just thinking on some super simplified interface where the ESP8266 handles everything. Imagine for example just copying a program in your PC transferred it to the calc like if you swiped a magnetic card on it

I see, wow that's aggressive, but it would simplify things on the device side. Perhaps the easiest approach is to somehow emulate (or use existent) 41 Extended memory in your new device that plugs into the port so that normal functions in the 41 can store and read programs and data. To be clear, by "easy" I mean easiest on the 41 side of things, where essentially no (or very minimal) software would be needed, but it still could exchange programs and data registers. Otherwise, you'll have to also write the 41-side MCODE for moving the data in and out.

Monte Dalrymple, creator of the 41CL, announced early work on a general purpose I/O board for 41 ports at HHC2018; you should check that out as it may be helpful as a kind of "middle-ware" for your planned device.

I think the easiest would be to do everything in the ESP Smile but I have no idea about the 41... I am more into the "newer" calculators. However I got a 33C weeks ago and started tinkering with my old calcs.

I see what Monte is doing is quite cool but there is not much published about. I would love to find open resources about the architecture, like a github repo with all the discoveries

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02-12-2019, 06:42 PM
Post: #10
RE: HP41 extension ports pinout
(02-11-2019 11:21 PM)eried Wrote:  
(02-11-2019 10:52 PM)rprosperi Wrote:  I see, wow that's aggressive, but it would simplify things on the device side. Perhaps the easiest approach is to somehow emulate (or use existent) 41 Extended memory in your new device that plugs into the port so that normal functions in the 41 can store and read programs and data. To be clear, by "easy" I mean easiest on the 41 side of things, where essentially no (or very minimal) software would be needed, but it still could exchange programs and data registers. Otherwise, you'll have to also write the 41-side MCODE for moving the data in and out.

Monte Dalrymple, creator of the 41CL, announced early work on a general purpose I/O board for 41 ports at HHC2018; you should check that out as it may be helpful as a kind of "middle-ware" for your planned device.

I think the easiest would be to do everything in the ESP Smile but I have no idea about the 41... I am more into the "newer" calculators. However I got a 33C weeks ago and started tinkering with my old calcs.

I see what Monte is doing is quite cool but there is not much published about. I would love to find open resources about the architecture, like a github repo with all the discoveries

What kind of information are you looking for?
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02-12-2019, 11:36 PM
Post: #11
RE: HP41 extension ports pinout
Eric, have a look at Meindert Kuiprs work on the MLDL2000 system. I believe he no longer builds and sells these development systems for the HP-41, but his web site is a true trove of information!

http://hp41.kuiprs.nl/hp41.htm

~Mark

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02-13-2019, 02:44 AM
Post: #12
RE: HP41 extension ports pinout
Potentially any existing module interface could be emulated by the esp8266.
Potentially:
HP-IL module to Mass storage
Card Reader
Cassette
Extended Memory as mentioned earlier.

I like the Card Reader housing as it should provide ample room for prototyping.

Try CC41!
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02-13-2019, 05:31 AM
Post: #13
RE: HP41 extension ports pinout
(02-13-2019 02:44 AM)Craig Bladow Wrote:  Potentially any existing module interface could be emulated by the esp8266.
Potentially:
HP-IL module to Mass storage
Card Reader
Cassette
Extended Memory as mentioned earlier.

I like the Card Reader housing as it should provide ample room for prototyping.

The ESP8266 draws 60mA during receive and 150-215mA (mode-dependent) during transmit. Might be a challenge for N batteries.
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02-13-2019, 12:22 PM
Post: #14
RE: HP41 extension ports pinout
(02-12-2019 06:42 PM)Monte Dalrymple Wrote:  What kind of information are you looking for?

In short words: just a basic pinout layout and protocol details for communication with cards. Something clean like what the community did with the HP Prime:
https://tiplanet.org/hpwiki/index.php?ti...ile_Format

Wifi is going to eat the batteries for sure, maybe I can include a small lipo. The esp8266 fits on a 3d printed housing easily and there is space available. I just ordered some NES and Genesis catridge slots to play with the contact assembly first.
[Image: esp8266_sleep_options.png?width=640&...ptions.png]

I think I have enough for now to start playing/reading. Thanks everyone!

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02-13-2019, 04:24 PM
Post: #15
RE: HP41 extension ports pinout
(02-13-2019 12:22 PM)eried Wrote:  
(02-12-2019 06:42 PM)Monte Dalrymple Wrote:  What kind of information are you looking for?

In short words: just a basic pinout layout and protocol details for communication with cards. Something clean like what the community did with the HP Prime:
https://tiplanet.org/hpwiki/index.php?ti...ile_Format

Wifi is going to eat the batteries for sure, maybe I can include a small lipo. The esp8266 fits on a 3d printed housing easily and there is space available. I just ordered some NES and Genesis catridge slots to play with the contact assembly first.
[Image: esp8266_sleep_options.png?width=640&...ptions.png]

I think I have enough for now to start playing/reading. Thanks everyone!

The chapter on "Timing" in http://systemyde.com/pdf/newt.pdf shows how the hp-41C bus works.
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