HP Forum Archive 01

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IR printer compatibility Message #1 Posted by Kevin on 31 Oct 1999, 6:58 a.m. Just wanted to know if the infrared printer 82240B is backwards compatible with the 82240A -- ie., can I print to an 82240B with my HP-41 and the infrared module 82242A? Also, if anyone knows, I was wondering what sort of protocol is used for communication with the IR printer.

Re: IR printer compatibility Message #2 Posted by Wayne Brown on 31 Oct 1999, 12:30 p.m., in response to message #1 by Kevin Yes, the printers are compatible. I bought my son an 82240B for use with his HP48GX, and it works just fine with my HP-41CV and IR module. I'm afraid I can't help you with the IR protocol, though.

Re: IR printer compatibility Message #3 Posted by Andrés C. Rodríguez on 1 Nov 1999, 7:23 a.m., in response to message #1 by Kevin There was a description of the IR printer protocol in an issue of the HP Journal, in the October 1987 issue.--- The article title and authors are: An Infrared Link for Low-Cost Calculators and Printers-- by Robert S. Worsley, Bruce A. Stephens, Steven L. Harper--- If memory helps, the protocol is similar to an asynchronous serial link, the bits are coded based on the timing of pulses that modulate a 32 khz carrier. It seems to be similar to the system used in infrared remote controls. It appends a 4-bit checksum to each byte, the strange detail is that the checksum is calculated by means of an AND function instead of the usual XOR.--- If you search this Forum and the archived Forum messages here at the Museum, you will find references to PC programs that intend to be compatible with this link, allowing transferring data from a calculator to a PC. I am not able to endorse any, since I have not tried them.

Re: IR printer compatibility Message #4 Posted by Reinhard Hawel on 1 Nov 1999, 8:55 a.m., in response to message #1 by Kevin You might want to try these links: http://www.users.kih.net/~hklingon/prj/hpir/ http://www.jarno.demon.nl/hp82240b.htm http://hpcalc.org/docs/misc/irprcom.txt http://www.users.kih.net/~hklingon/prj/hpir/hpirprot.txt Unfortunately I'm much behind the time with some of my projects. Maybe I'll write a short PIC program to operate the Printer sometimes.

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