HookuP for HP IR Calculators --- Any interest?

[Henry Prellwitz]

Hello, Ladies and Gents ---- I wondered if there was any interest in the HookuP device and software that was made by Rush Systems, for downloading information to a PC via the IR port on a 28C/28S, or from a 41, with the IR module. I have one of these that I bought from EduCALC over 10 years ago, and it still works fine! It's really handy for printing out long catalogs from HP41 modules. The device does not look too hard to build; and if there is interest out there in HP land, I'll carefully disassemble my example, and try to post a wiring diagram and part numbers for the electronic components. Does anyone know if Rush Systems is still in business, and would there be any legal problems reproducing this device, and the software? Thanks! --- Henry

[Andrés C. Rodríguez (Argentina)]

Count me as very interested!

[steve]

VERY INTERESTED.

How is this connected to the PC? I have been working on hardware and software to do this, but since I work *LOTS* it has been placed on the back burner more than once.

I felt sure that someone must have done it before, and I'm _really_ interested in how they did it.

[Henry Prellwitz]

OK, STeve;

The HookuP is connected to the PC via the serial port; mine came originally with a standard 25-pin female connector. The LED indicator light, as well as the rest of the device is powered from juice from the PC; no batteries! Well, I guess I'll have to carefully disassemble my HookuP, and try to give enough information for all of you to build one! I also have the software diskette, and the instruction manual, for those who may want copies. Cheers, --- Henry

[Thomas Falk]

Hi,

actually this has been done before, but for the HP28. Look e.g. into

http://nic.funet.fi/pub/misc/hp28s/hpread13.c

to find the program and some hints to the hardware. I have used the program with a similar hardware years ago get a backup from my HP28s and it works quite well. If there was only a way to get the information back into the calculator.

Greetings, Thomas

[steve]

Yeah, I looked at code similar to this, but the all important part -- the description of HOW to decode the pulse stream is not explained. It's just a mass of (for me at least) "write-only" C code.

I decoded the stream by detecting patterns, and fixed bytes by looking for best fit, and fixing missing pulses etc.

If anyone can decode this C and come up with a text (or pseudo code) description of the byte stream (or process) you'll be of great assistance to those of us who are c-illiterate.

[Thomas Falk]

Hi,

> If anyone can decode this C and come up with a text

> (or pseudo code) description of the byte stream

> (or process) you'll be of great assistance to those

> of us who are c-illiterate.

I would do it by myself, If I had the time. Looking around I found

http://www.funet.fi/pub/misc/hp28s/ir28

and the file "irdata" in the same directory. The code used is actually ascii, the code used for the special characters may be found in

http://www.ccl.kuleuven.ac.be/~luc/HP28/hardware/RS-232.html

Sorry for just posting WWW-adresses, but the information is out there ;-)

If you have questions regarding understanding C, please feel free to mail me. The problem with the code in "hpread13.c" is that the decoding has to be done in real time, therefore a lot of switching with the interrupts of the PC is done. If you want to include this code into some Windows program, there may be timing problems. A portable solution may be to do the decoding in a microcontroller and then using the normal RS232 for the connection to the PC.

Sounds like a lot of work. What system do you have in mind?

Thomas

[steve]

A far easier solution for the modern PC is to use the sound card :-)

Timing problems disappear.

[steve]

That information is very interesting. Thanks!

[Ian Phillips]

This sounds a wonderful idea, count me in

Ian