HP82143 emulation and virtual HP82153

[ThomasF]

My favorite calculator has always been the 41, and the main reason (at least for me) has been the I/O capabilities. I still remember when we got the PPC journal with the Lynn MLDL schematics and how we built some of these and with the VASM listings started to develop ML-code.

The 41 system was replaced when the 71B came along, and after that both the 42 and the 48 were used, but I always regretted that I replaced my 41 environment ...

Today I have restored some of that, both with some HP41's and the DM41X, and continued to develop things around it. With HP-IL and the PIL-Box, it is also easy to save and download programs to the 41's (which is not possible with ie. the 42).

I also recently built a RedEye receiver (using a ESP8266) to be able to send data from the calculators to the PC, but I also added a small display to it, so I could see the print output just as if it was printed on paper ...

When I (nostalgically) read old PPC- or CHHU-journals I wished that I had not got rid of my wand to the 41, and looking at the marketplace I find the wand to be way too expensive to motivate it. I still have all the original journals but nowadays I also have them online and I thought that it would be possible to scan them, so I decided to build my own wand!

Well, I realized that doing it with hardware would be tough, but making a “virtual” software wand would be possible - so off I went!

It turned out quite well, I managed to create a small C-application (for Linux) that would scan a barcode on the screen by clicking on either side of the barcode, just “like” a real wand and save the code in raw-format to be transferred to the calculator. Even quite poorly scanned barcodes worked, not always, but most of them.

Included here is a (poor) picture of the 41X which has been running the “SCDEMO” application, the applications (“SC” and “SCDEMO”) was “scanned” with the virtual wand from the online PPC-ROM manual and the resulting files was saved using USB to the calculator. Running the application it “printed” the output over IR to the emulated 82143 printer with the attached display. I can of course print the program as well and save the result on the PC, both as a graphic picture or as a text file (without the graphics).

Now I just have to figure out how I could build a module for the 41, eg. a PIC-processor connected to a ESP for WiFi-connection, so I could send data to a real 41 without using HPIL, ie. simulating a IR-wand or cardreader ... that would be fun!

Yes, sometimes I’m inventing the wheel again, but I learn a lot this way and I think it is fantastic how much there is to explore with a 44 year old system!

Cheers,
Thomas

[Jurgen Keller]

I'm also a big HP-41 fan and I like the barcode reader as well. Also a nice device for demos! Recently, I've created a video about printing barcode on a Thinkjet printer and on a plotter.

Your SCDEMO application looks to me a bit like what Martin Hepperle did:
A Software Decoder for HP-41 Barcodes

But maybe I've missed the details. Anyway, enjoy the project and let us know of your progress.

[floppy]

Very interesting. Could you print into a "raspberry pi" with (small) screen?

Since an HP41 can be connected to a PI and store its programs into a virtual drive (see there https://www.hpmuseum.org/forum/thread-19053.html), the virtual drive of the PI could become the exchange interface between the DM41X and the HP41.

For this, the pi could look at all raw file of the DM41X (when connected; with the use of a udev rule) then store all programms automatically into the virtual drive when the DM41X is detected (if any command for storing a raw file into a virtual drive under linux; must have a look if it exists; if not the raw file could hang in any area on the pi and by starting V41 on the pi screen, it could be loaded manually into the virtual drive).

Then later: connect the HP41 on the pi and you can upload.

[ThomasF]

Thanks!

(02-25-2023 05:39 PM)Jurgen Keller Wrote:  Your SCDEMO application looks to me a bit like what Martin Hepperle did:
A Software Decoder for HP-41 Barcodes

Well, "SC" was an application ("Special Characters") which was not included in the actual ROM but appeard in the manual, together with the "SCDEMO" application to just print a table with the "new" characters. I just used it as an example to print something.

Yes, I have seen Martins application (but have not tried it). I wanted something "simpler", ie. I don't need scanned images, I just show the barcodes on the display (from a web-page, pdf or whatever) and then click one each side of the barcode - if I can see the barcode on tmy screen then I can scan it. So I could open a manual or a journal and scroll through the pages and when I see the barcode I just start the application and click my mouse. But yes, basically they do the same thing ..

Cheers,
Thomas

[ThomasF]

(02-25-2023 05:57 PM)floppy Wrote:  Very interesting. Could you print into a "raspberry pi" with (small) screen?

Well yes, I think so. The RedEye interface is basically identical to the one Martin and Meindert made (see link below), but I used a ESP8266 instead and added a display. But the output is compatible, so using that one or mine connected to a RPi should work. The interface just returns the bytes sent from the calculator, so a small parser could collect the bytes and do what ever, ie. take a program listing and convert to a raw file.

RedEye interface

But, there is always a but, syntehic textstrings are basically not allowed, since the calculator (at least the DM41X) doesn't send every character, so these are missed and have to manually be updated.
But normal programs "should" work ...


Cheers,
Thomas