Questions about printing, printing and printing - Hewlett Packard

This is a discussion on Questions about printing, printing and printing - Hewlett Packard ; Hi everybody. A friend of mine give me two HP calculators he dont'use anymore: an HP-28S and an HP-17BII. Including my HP-49G+, now I have 3 HP calculators that are able to print (on a "grand total" of 6 HP ...

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Thread: Questions about printing, printing and printing

  1. Questions about printing, printing and printing

    Hi everybody.

    A friend of mine give me two HP calculators he dont'use anymore: an HP-28S
    and an HP-17BII. Including my HP-49G+, now I have 3 HP calculators that are
    able to print (on a "grand total" of 6 HP calculators). I would like to
    print something but I don't want to spend too much (my wife can't
    understand).

    Now the questions:

    1. Are some printers out there compatible with the 3 calcs?

    2. Do you know if is there a IR printer server that can be connected to an
    external printer (USB, parallel, RS232, etc.).

    3. Do know if is possibile to use a PC as a printer gateway for the 3
    calculators?

    Do you have some suggestions?

    Massimo Santin

    P.S.: I posted this message on MoHPC forum, too.


  2. Re: Questions about printing, printing and printing

    On Wed, 11 Apr 2007 15:52:50 -0500, Massimo Santin wrote:

    > A friend of mine give me two HP calculators he dont'use anymore: an HP-28S
    > and an HP-17BII. Including my HP-49G+, now I have 3 HP calculators that are
    > able to print (on a "grand total" of 6 HP calculators). I would like to
    > print something but I don't want to spend too much (my wife can't
    > understand).
    >
    > Now the questions:
    >
    > Are some printers out there compatible with the 3 calcs?


    Only HP82240[B] -- HP's original, battery-operated,
    thermal printer (requires thermal paper rolls),
    which is no longer manufactured
    (but try eBay or hpmuseum.org).

    http://www.google.com/search?q=HP82240B
    http://www.google.com/search?q=HP+82240B

    There is (or was) another manufacturer whose printer
    is similar and compatible, though I forgot the brand

    > Do you know if is there a IR printer server that can be
    > connected to an external printer (USB, parallel, RS232, etc.)


    Neat idea; who'll build one?

    Or did any of those makers of external serial IR modules for PC
    ever happen to make one for HP's proprietary IR encoding?

    > Do know if is possibile to use a PC as a printer gateway
    > for the 3 calculators?


    http://www.jarno.demon.nl/hp82240b.htm

    > Do you have some suggestions?


    Any HP48[S/G] (which maybe someone else will give you too
    can run a program called INPRT,
    which can receive text printing aimed at an HP82240B,
    capturing it in a string, which can then be transmitted elsewhere.

    http://www.hpcalc.org/search.php?query=inprt
    (the 877-byte version of 1994.01.04
    is supposed to work in both G[X] and S[X],
    as declared in the original on Joe Horn's Goodies Disk #9)

    > P.S.: I posted this message on MoHPC forum, too.


    I hope they weren't so preoccupied being [c]rude to newbies
    that they had more time to offer you an answer.

    -[ ]-

  3. Re: Questions about printing, printing and printing

    Seen:
    > http://www.google.com/search?q=HP82240B
    > http://www.google.com/search?q=HP+82240B


    Google trick:

    Use the following query to get results for both of the above at once, and
    also HP-82240B:
    http://www.google.com/search?q=HP-82240B

    Regards,

    Eric Rechlin



  4. Re: Questions about printing, printing and printing


    > "John H Meyers" wrote in message
    > newsp.tqoztooxnn735j@w2kjhm.ia.mum.edu...
    > On Wed, 11 Apr 2007 15:52:50 -0500, Massimo Santin wrote:
    >
    > > 1. Are some printers out there compatible with the 3 calcs?

    > Only HP82240[B] -- HP's original, battery-operated,
    > thermal printer (requires thermal paper rolls),
    > which is no longer manufactured
    > (but try eBay or hpmuseum.org).


    To summarize what I understand from your answer and from some Google
    searches: HP-28, HP-48 and HP-17BIII use a specific HP IR protocol
    (Redeye?); HP-49G+ uses HP protocol for printing and IrDA for data transfer.

    More questions:

    1) It is possible to print from an HP-49G+ via IrDA to an IrDA enabled
    printer?
    2) An HP-49G+ is able to communicate via IR with an old HP-48 or HP-28?
    3) It is possible to write an INPRT program for the HP-49G+ that can receive
    printing from old HP?

    > > Do you know if is there a IR printer server that can be
    > > connected to an external printer (USB, parallel, RS232, etc.)

    > Neat idea; who'll build one?


    I think it will not be complicated but as you said...

    > Or did any of those makers of external serial IR modules for PC
    > ever happen to make one for HP's proprietary IR encoding?


    ....IrDA rulez! And HP calculators market is small, I suppose.

    > > Do know if is possibile to use a PC as a printer gateway
    >> for the 3 calculators?

    >
    > http://www.jarno.demon.nl/hp82240b.htm


    Interesting but with some defects: it is an old DOS program; it is able to
    run only on a serial link. Eventually it is possible to use it on IrDA COMM
    emulation (like IrCOMM2K for Windows) but I'm not able to use it with the
    HP-49G+ (see my previous questions). Can be my fault?

    > > Do you have some suggestions?

    > Any HP48[S/G] (which maybe someone else will give you too


    I'm working on that! ;-) And probably I need to work on getting an HP
    printer, too!

    > can run a program called INPRT,
    > which can receive text printing aimed at an HP82240B,
    > capturing it in a string, which can then be transmitted elsewhere.
    >
    > http://www.hpcalc.org/search.php?query=inprt
    > (the 877-byte version of 1994.01.04
    > is supposed to work in both G[X] and S[X],
    > as declared in the original on Joe Horn's Goodies Disk #9)


    > > P.S.: I posted this message on MoHPC forum, too.

    > I hope they weren't so preoccupied being [c]rude to newbies
    > that they had more time to offer you an answer.


    Actually I had some kindly answers.

    And I want to thank you for your answers, too.

    Massimo Santin




  5. Re: Questions about printing, printing and printing

    On Fri, 13 Apr 2007 07:59:56 -0500, Massimo Santin wrote:

    > To summarize what I understand from your answer
    > and from some Google searches: HP28, HP48 and HP17B[II]
    > use a specific HP IR protocol (Redeye?)


    All of those which print to the "Redeye" printer
    use its physical-layer protocol while printing;
    since HP28/17B/18C/19B/42S/etc. can do nothing else but print
    (one-way transfer), that's the only output they have, while HP48
    is also conversant with bi-directional "SIR" (serial over IR),
    which is more standard, relying on higher-level protocols
    such as Kermit and XModem to provide error detection/retry.

    The HP48 series uses flag -34
    to choose "Redeye" [clear] vs. SIR [set] for "print" commands;
    it's actually flag -33 which really chooses wire [clear] vs IR [set],
    so if you set both flags it "prints" via SIR instead of via "Redeye."

    In any case, "printing" is always one-way transfer, whereas
    SEND/RECV/RECN/XSEND/XRECV are via "duplex" Kermit/XModem protocols
    (half-duplex over IR, to eliminate reflections being "received"
    at the same time as they are being sent).

    > HP49G+ uses HP protocol for printing and IrDA for data transfer.


    I've never tested the 50G/49G+ IR printing, but if the Redeye printer
    understands it, perhaps also the HP48 using the INPRT library,
    which would make possible one-way transfer from HP50/49G+ to HP48[S/G]
    via "printing," sans error correction.

    > More questions:
    >
    > Is it possible to print from an HP49G+ via IrDA
    > to an IrDA enabled printer?


    Someone should certainly have tried that by now

    > An HP49G+ is able to communicate via IR with an old HP48 or HP28?


    The HP28/17B/18C/19B/42S/etc. are "print-only,"
    so do you mean the next question below?

    > It is possible to write an INPRT program for the HP49G+
    > that can receive printing from old HP?


    There's this talk about "different wavelengths,"
    but if it's close enough that 49G+ can get a "Redeye" printer to receive,
    why couldn't HP48[S/G] also receive it (via INPRT), and vice-versa?

    If that small wavelength difference can be overcome, however,
    there's still the small matter of writing an INPRT for the 49G+
    (but hey, if this can be done, why not also bi-directional SIR,
    which would offer much better 2-way file transfer?)

    >> http://www.jarno.demon.nl/hp82240b.htm

    >
    > Interesting but with some defects: it is an old DOS program; it is able to
    > run only on a serial link. Eventually it is possible to use it on IrDACOMM
    > emulation (like IrCOMM2K for Windows) but I'm not able to use it with the
    > HP49G+ (see my previous questions). Can be my fault?


    If it works with 28S/17B etc. but not 49G+ then perhaps there's either
    not enough power in 49G+ to overcome any wavelength discrepancy,
    or what else could it be?

    Once upon a time, there were "IR power boosters" to slip onto
    weak TV remotes (said to have been an invention of Steve Wozniak);
    it could be interesting to either find or build one now,
    and see whether that could boost the deliberately weakened power
    of HP IR outputs (to the chagrin of educators and test proctors).

    > I'm working on [getting an HP48S/G]
    > And probably I need to work on getting an HP printer, too!


    All are probably still randomly available,
    via the usual suspicious places

    The following will find more 82240 emulators for PC, as well as
    the official "HP82240B Technical Interfacing Guide"
    and "HP48 I/O Technical Interfacing Guide" documents,
    explaining the physical and logical printer protocols:
    http://www.hpcalc.org/search.php?que...rfacing&hp48=1

    [r->] [OFF]

  6. Re: Questions about printing, printing and printing

    Hi again, Massimo,

    I'm not John, but I'll try to answer at least some of your
    additional questions.

    Massimo Santin (at GMail) wrote:
    >> "John H Meyers" wrote in message
    >> newsp.tqoztooxnn735j@w2kjhm.ia.mum.edu...
    >> On Wed, 11 Apr 2007 15:52:50 -0500, Massimo Santin wrote:
    >>
    >>> 1. Are some printers out there compatible with the 3 calcs?

    >> Only HP82240[B] -- HP's original, battery-operated,
    >> thermal printer (requires thermal paper rolls),
    >> which is no longer manufactured
    >> (but try eBay or hpmuseum.org).

    >
    > To summarize what I understand from your answer and from some Google
    > searches: HP-28, HP-48 and HP-17BIII use a specific HP IR protocol
    > (Redeye?); HP-49G+ uses HP protocol for printing and IrDA for data transfer.


    All of these models use the same "RedEye" protocol for printing to
    the 82240A/B printers and the Martel Instruments models that are
    "HPIR" capable.

    For data transfer via IR, the 48 series use "Serial IR", and the
    49 series that have IR (49g+, 48gII, and 50g) use IrDA.

    The 28 series doesn't have any built-in capability for receiving
    data at all. I've read of hardware modifications to allow the 28
    series to receive, at least via wire, but when the 48SX became
    available, it was easier to just buy that instead.

    > More questions:
    >
    > 1) It is possible to print from an HP-49G+ via IrDA to an IrDA enabled
    > printer?


    I don't have an IrDA capable printer, but I guess so, as long as
    the printer has a built-in font. That is, if it can treat a byte
    as a character and not require that data be sent to it in a
    graphical format, otherwise you'd have to develop a program to
    convert it to a format that the printer can use.

    I do have an RS-232/IrDA converter that I can use with
    HyperTerminal, and using HyperTerminal's "Capture Text..."
    capability, I can "print" to it via IrDA from a 49g+ or 50g. The
    system flag settings required for this are -34 set (Print via
    wire) and -33 set (Transfer via IR).

    More accurately, flag -34 clear would be "print via RedEye IR" and
    flag -34 set would be "print via current I/O port".

    > 2) An HP-49G+ is able to communicate via IR with an old HP-48 or HP-28?


    No. The 49 series use IrDA and the 48 series use "Serial IR", so
    direct "via IR" communications between them aren't possible.

    The 28 series can't receive, and they transmit only using the
    RedEye encoding for the printers, which the 49 series doesn't
    receive (unless someone comes up with a 49 series INPRT program).

    Besides that, the 49 series have both a reduced IR sensitivity and
    a reduced IR transmitting level, while the 48 series have only a
    even more reduced IR sensitivity, all to assure the educational
    community that the IR capabilities won't be used for surreptitious
    communications. It may be possible to overcome these restrictions
    with some hardware hacking, but I think that HP wouldn't
    appreciate anyone publicizing how to do that.

    I've tried using an INPRT program on a 48 to try to receive RedEye
    printing from a 49g+, but apparently the combination of low IR
    signal output on the 49g+ with low IR sensitivity on the 48
    prevented that from working.

    > 3) It is possible to write an INPRT program for the HP-49G+ that can receive
    > printing from old HP?


    It may be. Perhaps someone could dig into the existing INPRT
    programs and port one of them to the 49 series. But as far as I
    know, no one has yet.

    By the way, the INPRT programs that HP made available also
    remapped (where possible) non-ASCII characters from the Roman 8
    character set used on the 28 series to the modified ECMA 94 Latin
    no. 1 character set used on the 48 series, because transferring
    from the 28 series to the 48 series is the intended use.
    Variations on INPRT that don't do any remapping (or, maybe,
    "remap" each non-ASCII character to itself) are also available.

    >>> Do you know if is there a IR printer server that can be
    >>> connected to an external printer (USB, parallel, RS232, etc.)

    >> Neat idea; who'll build one?

    >
    > I think it will not be complicated but as you said...


    Well, HP has made the details of the "RedEye" protocol available.
    Note that various other devices such as some medical and
    automotive test devices are designed to use the 82240 printers.
    Presumably one could design a device that would receive the RedEye
    signal, optionally use the 4 ECC bits for error detection or
    correction, and decode each 12-bit frame to an 8-bit byte, which
    could be output using whichever method one desired.

    >
    >> Or did any of those makers of external serial IR modules for PC
    >> ever happen to make one for HP's proprietary IR encoding?

    >
    > ....IrDA rulez! And HP calculators market is small, I suppose.


    Well, yes, IrDA is a good protocol, although much more complicated
    than the Serial IR communications or even the RedEye encoding
    which both came earlier.

    I suppose that HP calculators do have a relatively small market,
    and it doesn't even market a printer capable of receiving RedEye
    signals any more. I'm just glad that they include RedEye printing
    capability on the 49g+, 48gII, and 50g.

    Maybe someday HP will market a more-or-less hand-held sized IrDA
    capable printer, although I'd suspect it of being a rebadged
    Martel model.

    >
    >>> Do know if is possibile to use a PC as a printer gateway
    >>> for the 3 calculators?

    >> http://www.jarno.demon.nl/hp82240b.htm

    >
    > Interesting but with some defects: it is an old DOS program; it is able to
    > run only on a serial link. Eventually it is possible to use it on IrDA COMM
    > emulation (like IrCOMM2K for Windows) but I'm not able to use it with the
    > HP-49G+ (see my previous questions). Can be my fault?
    >
    >>> Do you have some suggestions?

    >> Any HP48[S/G] (which maybe someone else will give you too

    >
    > I'm working on that! ;-) And probably I need to work on getting an HP
    > printer, too!


    Good luck on those! But I suppose that there are some HP
    calculators out there that are unused because the current owners
    can't find the = key, and some printers that just don't seem to
    work with IrDA....

    >> can run a program called INPRT,
    >> which can receive text printing aimed at an HP82240B,
    >> capturing it in a string, which can then be transmitted elsewhere.
    >>
    >> http://www.hpcalc.org/search.php?query=inprt
    >> (the 877-byte version of 1994.01.04
    >> is supposed to work in both G[X] and S[X],
    >> as declared in the original on Joe Horn's Goodies Disk #9)

    >
    >>> P.S.: I posted this message on MoHPC forum, too.

    >> I hope they weren't so preoccupied being [c]rude to newbies
    >> that they had more time to offer you an answer.

    >
    > Actually I had some kindly answers.


    Yes, but, actually, this newsgroup is normally the better place
    for discussions of RPL models, as the Museum understandably tends
    to be biased in favour of the "Classic RPN" models.

    By the way, you can do a Google search of the archive of this
    usenet group all the way back to 1991; that way, you can often
    find the answer to your questions without even asking. See:
    http://groups.google.com/group/comp.sys.hp48/

    > And I want to thank you for your answers, too.


    --
    Regards,
    James


  7. Re: Questions about printing, printing and printing

    John H Meyers wrote:
    > On Fri, 13 Apr 2007 07:59:56 -0500, Massimo Santin wrote:
    >
    >> To summarize what I understand from your answer
    >> and from some Google searches: HP28, HP48 and HP17B[II]
    >> use a specific HP IR protocol (Redeye?)

    >
    > All of those which print to the "Redeye" printer
    > use its physical-layer protocol while printing;
    > since HP28/17B/18C/19B/42S/etc. can do nothing else but print
    > (one-way transfer), that's the only output they have, while HP48
    > is also conversant with bi-directional "SIR" (serial over IR),
    > which is more standard, relying on higher-level protocols
    > such as Kermit and XModem to provide error detection/retry.
    >
    > The HP48 series uses flag -34
    > to choose "Redeye" [clear] vs. SIR [set] for "print" commands;
    > it's actually flag -33 which really chooses wire [clear] vs IR [set],
    > so if you set both flags it "prints" via SIR instead of via "Redeye."
    >
    > In any case, "printing" is always one-way transfer, whereas
    > SEND/RECV/RECN/XSEND/XRECV are via "duplex" Kermit/XModem protocols
    > (half-duplex over IR, to eliminate reflections being "received"
    > at the same time as they are being sent).
    >
    >> HP49G+ uses HP protocol for printing and IrDA for data transfer.

    >
    > I've never tested the 50G/49G+ IR printing,


    I have...

    > but if the Redeye printer
    > understands it,


    and it does, but with a drastically reduced range of maybe a
    couple of inches from the 49g+ and 50g, compared with a yard or
    two from the 48SX/GX.

    > perhaps also the HP48 using the INPRT library,
    > which would make possible one-way transfer from HP50/49G+ to HP48[S/G]
    > via "printing," sans error correction.


    I've tried that, and it doesn't work.

    >> More questions:
    >>
    >> Is it possible to print from an HP49G+ via IrDA
    >> to an IrDA enabled printer?

    >
    > Someone should certainly have tried that by now


    If I recall correctly, someone did and it worked, at least with
    his printer, although with a reduced range, and the IrDA
    "connection" had to be already established before executing the
    printing command, else the first few bytes would be lost. A
    thorough search of the newsgroup archive would probably find the
    answer to that question.

    Maybe someone who has an IrDA capable printer and a 48gII, 49g+,
    or 50g would be good enough to experiment and let us know?

    >> An HP49G+ is able to communicate via IR with an old HP48 or HP28?

    >
    > The HP28/17B/18C/19B/42S/etc. are "print-only,"
    > so do you mean the next question below?
    >
    >> It is possible to write an INPRT program for the HP49G+
    >> that can receive printing from old HP?

    >
    > There's this talk about "different wavelengths,"


    Which prompted me to do a bit of research.

    For transmitting to the 82240B:

    "The optimum optical wavelength for the printer is 940
    nanometers (nm), but wavelengths as short as 850 nm and as long
    as 1000 nm can be used with only minor reductions in the
    distance over which data can be sent to the printer."

    For the 48 series IR, the specification calls for a typical
    wavelength of 940nm, with the minimum and maximum unspecified.

    IrDA doesn't specify a "typical" wavelength, but calls for a peak
    wavelength with a minimum of 850nm and a maximum of 900nm.

    So there should be a difference in wavelength, although the 82240
    printers do manage to receive the RedEye signal from the 49g+ and
    50g.

    I'd guess that an IR receiver would be sensitive to a fairly wide
    range of wavelengths.

    > but if it's close enough that 49G+ can get a "Redeye" printer to receive,
    > why couldn't HP48[S/G] also receive it (via INPRT),


    Note that the 49 series has to be much closer to the printers than
    other models do, and for INPRT to work on a 48 series, the RedEye
    transmitter has to be a lot closer to the 48 than for transmitting
    to a printer. How close is "closer than closer"?

    My guess is that it's mostly a matter of the IR signal from the 49
    series being weaker than the IR signal from other models, with the
    difference in wavelengths also contributing.

    > and vice-versa?
    >
    > If that small wavelength difference can be overcome, however,
    > there's still the small matter of writing an INPRT for the 49G+


    For receiving a RedEye signal with an INPRT program on the 49
    series, my reasoning is similar to yours.

    My guess is that the 49 series is capable of receiving the RedEye
    (and SIR, for that matter) signal, but doesn't recognize the
    encoding, so it might be possible for an INPRT program to be
    written for the 49 series, and come to think of it, it might be
    possible to write a program for the 49 series to receive SIR from
    the 48 series.

    > (but hey, if this can be done, why not also bi-directional SIR,
    > which would offer much better 2-way file transfer?)
    >
    >>> http://www.jarno.demon.nl/hp82240b.htm

    >> Interesting but with some defects: it is an old DOS program; it is able to
    >> run only on a serial link. Eventually it is possible to use it on IrDA COMM
    >> emulation (like IrCOMM2K for Windows) but I'm not able to use it with the
    >> HP49G+ (see my previous questions). Can be my fault?

    >
    > If it works with 28S/17B etc. but not 49G+ then perhaps there's either
    > not enough power in 49G+ to overcome any wavelength discrepancy,
    > or what else could it be?


    But John, my understanding is that that program depends on a
    connection to a COM port, so how could it work it work with RedEye
    printing? It seems to me that to use it with any IR signal,
    hardware to convert it to an RS-232 compatible signal would be
    needed. Certainly it ought to work with an RS-232/IrDA converter
    and virtual COM port, or an RS-232/SIR converter, but where do we
    find an RS-232/RedEye converter?

    > Once upon a time, there were "IR power boosters" to slip onto
    > weak TV remotes (said to have been an invention of Steve Wozniak);
    > it could be interesting to either find or build one now,
    > and see whether that could boost the deliberately weakened power
    > of HP IR outputs (to the chagrin of educators and test proctors).


    I've read of these boosters, as well as boosters that don't slip
    onto a remote but are placed elsewhere, with the intention being
    to boost the signal enough that it could find its way (via
    reflections) around obstacles, into other rooms (assuming an open
    door), and so on. It seems to me that something like that might
    work with the calculators.

    I'd think that such a device would be obvious enough for educators
    and test proctors to easily notice. What would be more of a
    concern would be internal hardware modifications to boost the IR
    signal power or sensitivity.

    But hey, with so many students carrying cell phones and
    Wi-Fi-capable hand-held game gadgets, why would they bother trying
    to use a calculator for communications?

    >> I'm working on [getting an HP48S/G]
    >> And probably I need to work on getting an HP printer, too!

    >
    > All are probably still randomly available,
    > via the usual suspicious places
    >
    > The following will find more 82240 emulators for PC, as well as
    > the official "HP82240B Technical Interfacing Guide"
    > and "HP48 I/O Technical Interfacing Guide" documents,
    > explaining the physical and logical printer protocols:
    > http://www.hpcalc.org/search.php?que...rfacing&hp48=1


    --
    Regards,
    James


  8. Re: Questions about printing, printing and printing

    On Fri, 13 Apr 2007 21:57:35 -0500, James M. Prange contributed:

    > I'm not John


    Aren't "James" and "John" nearly the same,
    in Approximate mode? ;-)

    > Martel Instruments


    Thanks for finding that manufacturer!
    http://www.martelinstruments.com/pro...on/mcp7800.htm
    http://www.martelinstruments.com/pro...on/mcp8800.htm

    > For data transfer via IR, the 48 series use "Serial IR",
    > and the 49 series that have IR (49g+, 48gII, and 50g) use IrDA.


    Physical layer, anyway.

    >> It is possible to print from an HP-49G+ via IrDA
    >> to an IrDA enabled printer?

    >
    > I don't have an IrDA capable printer, but I guess so, as long as
    > the printer has a built-in font. That is, if it can treat a byte
    > as a character and not require that data be sent to it in a
    > graphical format, otherwise you'd have to develop a program to
    > convert it to a format that the printer can use.


    Do IrDA printers need any higher IrDA protocol layers?
    http://www.actisys.com/article.html
    http://www.irda.org/

    That might be the company whose SIR adapter I have,
    but all their pages appear frozen in time (Win95/98/CE)
    so who knows what you can or can't get:
    http://www.actisys.com/actir100.html
    http://www.compusb.com/irprinadfora.html
    http://www.actisys.com/IrDAProd.html

    > I do have an RS-232/IrDA converter that I can use with
    > HyperTerminal, and using HyperTerminal's "Capture Text..."
    > capability, I can "print" to it via IrDA from a 49g+ or 50g.


    This may suggest that only the "physical" layer is used
    (but surely there are folks reading who know all about this,
    just haven't spoken up yet

    > The system flag settings required for this are -34 set
    > (Print via wire) and -33 set (Transfer via IR).
    >
    > More accurately, flag -34 clear would be "print via RedEye IR"
    > and flag -34 set would be "print via current I/O port".


    > The 49 series use IrDA and the 48 series use "Serial IR", so
    > direct "via IR" communications between them aren't possible.


    I wonder just how similar or different these are?
    Doesn't the ARM package come with built-in serial UARTs?

    > the 49 series have both a reduced IR sensitivity and
    > a reduced IR transmitting level, while the 48 series have only a
    > even more reduced IR sensitivity, all to assure the educational
    > community that the IR capabilities won't be used for surreptitious
    > communications. It may be possible to overcome these restrictions
    > with some hardware hacking, but I think that HP wouldn't
    > appreciate anyone publicizing how to do that.


    In the HP48, changing some resistor allowed higher output power, IIRC.

    > I've tried using an INPRT program on a 48 to try to receive RedEye
    > printing from a 49g+, but apparently the combination of low IR
    > signal output on the 49g+ with low IR sensitivity on the 48
    > prevented that from working.


    That's really sad news :-((

    > Well, HP has made the details of the "RedEye" protocol available.
    > Note that various other devices such as some medical and
    > automotive test devices are designed to use the 82240 printers.


    Cool, where can I aim my printer to get my engine data? ;-)

    > Well, yes, IrDA is a good protocol, although much more complicated
    > than the Serial IR communications or even the RedEye encoding
    > which both came earlier.


    Again, is this about physical layer, or the other "IrDA stack" stuff?

    > [hpmuseum.org] understandably tends
    > to be biased in favour of the "Classic RPN" models.


    They go well into the latter half of the last century:
    "Some Interesting Later Models (1986)"

    But they do have one more final page:
    "The Other Models"
    http://www.hpmuseum.org/therest.htm
    [where HP50G remains undiscovered :]

    Maybe it's like U.S. postage stamps --
    any depicted person has to be long dead

    -[ ]-

  9. Re: Questions about printing, printing and printing

    On Sat, 14 Apr 2007 04:06:47 -0500, James M. Prange wrote:

    > But my understanding is that that program depends on a
    > connection to a COM port, so how could it work it work with RedEye
    > printing? It seems to me that to use it with any IR signal,
    > hardware to convert it to an RS-232 compatible signal would be
    > needed. Certainly it ought to work with an RS-232/IrDA converter
    > and virtual COM port, or an RS-232/SIR converter,
    > but where do we find an RS-232/RedEye converter?


    Some company (Aegis?) that sent me an evaluation sample of an SIR
    receiver for potential HP48 use was evidently considering making one,
    but I don't know whether they (or anyone else) ever did;
    if this protocol was so popular for medical or automotive readouts,
    that could have inspired some alternate PC-based solutions
    (or even alternate mobile computing device solutions -- did
    HP95/100/200LX ever handle it?)

    The internals of the printer do it (both HP's printer and Martel's),
    so maybe there's a way to add an extra serial port to one of
    those printers, the way HP has added an extra serial port
    to an HP50, and use a printer itself as a converter for computers

    I wonder whether a TV "learning remote" can learn all the codes?

    Are there any cellphone/PDAs that can also "learn" IR remote control codes?
    (interesting possibilities there -- after all, there have been
    "TV learning remote" programs which run on an HP48!)

    Apparently there do exist "raw" IR receivers which go into
    serial/USB ports, and in that case, PC software could take over
    the responsibility to decode it. The possibilities are staggering

    > I've read of these boosters, as well as boosters that don't slip
    > onto a remote but are placed elsewhere, with the intention being
    > to boost the signal enough that it could find its way (via
    > reflections) around obstacles, into other rooms (assuming an open
    > door), and so on. It seems to me that something like that might
    > work with the calculators.
    >
    > I'd think that such a device would be obvious enough for educators
    > and test proctors to easily notice. What would be more of a
    > concern would be internal hardware modifications to boost the IR
    > signal power or sensitivity.
    >
    > But hey, with so many students carrying cell phones and
    > Wi-Fi-capable hand-held game gadgets, why would they bother trying
    > to use a calculator for communications?


    "Because it's there"

    Have you tried an external lens yet, to focus the IR beam better?
    (the Brinkmann LED flashlight I'm holding has a lens in front
    of its one LED and reflector, and that lens does focus the light
    into a narrow spot -- all we need is to be sure the lens material
    passes IR very well.

    So I guess I wasn't thinking about decoding the "Redeye" IR in the computer,
    but look at all the possibilities that you've meanwhile uncovered

    [r->] [OFF]

  10. Re: Questions about printing, printing and printing

    OK. Now I need time (spare time = very precious) to assimilate the
    informations that all you give me.
    I will try to write a document to summarize the discussion. Then I will post
    it for comments.

    Massimo Santin


  11. Re: Questions about printing, printing and printing

    John H Meyers wrote:
    > On Fri, 13 Apr 2007 21:57:35 -0500, James M. Prange contributed:
    >
    >> I'm not John

    >
    > Aren't "James" and "John" nearly the same,
    > in Approximate mode? ;-)


    Approximately, but not of course exactly.

    A disclaimer: I'm no expert on IrDA, and most of the technical
    information that I've found about it seems to be written by
    experts for experts. But perhaps the writers aren't so expert in
    using the English language? Anyway, reading it tends to confuse
    me, so I may well be wrong in some of what I write about it here.

    You could think of the area in the range of IrDA devices as being
    sort of a data bus that has to be able to handle devices being
    suddenly connected or disconnected, and a fair amount of noise
    possibly present, so a lot of "handshaking" is always going on.

    >> Martel Instruments

    >
    > Thanks for finding that manufacturer!
    > http://www.martelinstruments.com/pro...on/mcp7800.htm
    > http://www.martelinstruments.com/pro...on/mcp8800.htm


    Someone from that company was kind enough to e-mail me a lot of
    information about the models that I'm interested in, but failed to
    include prices or where or how to buy them. Perhaps Martel
    Instruments isn't set up for direct retail sales, but surely he
    should've been able to refer me to someone that was. Maybe it's a
    case of "if you have to ask the price, then you can't afford it"?
    Anyway, I haven't gotten around to asking those questions.

    >> For data transfer via IR, the 48 series use "Serial IR",
    >> and the 49 series that have IR (49g+, 48gII, and 50g) use IrDA.


    Just to make things interesting, IrDA also uses the term "Serial
    Infrared" for it's communications, and in particular, lists this
    definition:

    SIR = Serial Infrared (used to describe infrared data
    transmission up to and including 115.2 kbit/s; obsolete term)

    I'll use these only to refer to the IR used for the 48 series I/O.

    > Physical layer, anyway.


    From what I understand, to qualify as "IrDA", as well as the
    "Physical Layer", the "Link Access Protocol" (IrLAP) and "Link
    Management Protocol" (IrLMP) layers are also mandatory, although
    not all features of any of them are required.

    >>> It is possible to print from an HP-49G+ via IrDA
    >>> to an IrDA enabled printer?

    >> I don't have an IrDA capable printer, but I guess so, as long as
    >> the printer has a built-in font. That is, if it can treat a byte
    >> as a character and not require that data be sent to it in a
    >> graphical format, otherwise you'd have to develop a program to
    >> convert it to a format that the printer can use.

    >
    > Do IrDA printers need any higher IrDA protocol layers?


    Good question; I wish that I knew how much they really need. It
    seems to me that they need at least IrLAP to establish how to
    communicate, take care of flow control, error management, and so
    on, and IrLMP to keep track of who's talking to whom. In the case
    of the Martel models, I *guess* that "IrDA Phys" does include
    these, and that "IrDA Stack" includes additional layers.

    Of course "HP IR" as used by Martel would mean the RedEye encoding
    as used with the HP 82240A/B.

    > http://www.actisys.com/article.html
    > http://www.irda.org/
    >
    > That might be the company whose SIR adapter I have,
    > but all their pages appear frozen in time (Win95/98/CE)
    > so who knows what you can or can't get:
    > http://www.actisys.com/actir100.html
    > http://www.compusb.com/irprinadfora.html
    > http://www.actisys.com/IrDAProd.html
    >
    >> I do have an RS-232/IrDA converter that I can use with
    >> HyperTerminal, and using HyperTerminal's "Capture Text..."
    >> capability, I can "print" to it via IrDA from a 49g+ or 50g.


    By the way, I now also have a USB/IrDA converter that can do the
    same. At first, I thought that it didn't work, but eventually I
    found that I can switch from one converter to the other by first
    uninstalling one and only then installing the other.

    > This may suggest that only the "physical" layer is used


    Well, a "connection" is established and maintained, so I think
    that at least the IrLAP and IrLMP layers are also used.

    Information from my Infrared Monitor window while connected (but
    not necessarily sending or receiving data), using my RS-232/IrDA
    converter:

    Infrared communication is in progress.

    Communicating with:

    Name: XTNDAccess 9-Wire
    Description: XTNDAccessIrDA Stack

    Communication efficiency (affected by positioning,
    obstructions, lighting, etc.)

    Good at 115.2 kbps
    (No or few transmissions)

    By the way, having a fresh battery in the calculator (even if the
    old one wasn't causing a low battery warning) seems to make it a
    lot easier to establish and maintain a connection.

    > (but surely there are folks reading who know all about this,
    > just haven't spoken up yet
    >
    >> The system flag settings required for this are -34 set
    >> (Print via wire) and -33 set (Transfer via IR).
    >>
    >> More accurately, flag -34 clear would be "print via RedEye IR"
    >> and flag -34 set would be "print via current I/O port".

    >
    >> The 49 series use IrDA and the 48 series use "Serial IR", so
    >> direct "via IR" communications between them aren't possible.

    >
    > I wonder just how similar or different these are?


    It looks to me as if the IrDA "Physical Layer", for speeds up to
    115200bps (bits per second), is a lot like the 48 series SIR.
    Since HP was one of the founding members of the association, I
    don't find that to be very surprising.

    IrDA at speeds above 115200bps has some significant differences.
    The following applies only the lower speeds.

    I've already mentioned that the wavelengths differ (although
    they're perhaps "close enough").

    Both SIR and IrDA are "half duplex", that is, each device can
    transmit and receive, but can't do both at the same time.

    SIR's speed is always 2400bps nominal, with a minimum of 2340bps
    and a maximum of 2460bps, but the only mandatory speed for IrDA is
    9600bps, with 2400bps (+/-0.87%, or about 2379-2421bps) being
    optional. IrDA always starts a "connection" at 9600bps until some
    basic parameters are negotiated, but that's a requirement of the
    IrLAP layer, not of the physical layer.

    A "bit time" at 2400bps is about 416.67us. The SIR pulse width is
    nominally 52us (about 1/8 bit time), with a minimum of 40us and a
    maximum of 80us, compared to it being nominally 3/16 bit time with
    IrDA, but IrDA allows a lot more tolerance, at 2400bps, nominally
    78.13us, with a minimum of 1.41us and a maximum of 88.55us.
    Presumably, the 49 series would use the built-in IrDA mode of its
    UART, so about 3/16 bit time, near the high end of SIR's allowable
    pulse width.

    The modulation for both types is known as RZI (Return to Zero,
    Inverted); a logical 0 is represented as a bit time with a pulse,
    and a logical 1 as a bit time without a pulse. SIR transmits each
    byte as 1 start bit (logical 0, pulse), 8 data bits (least
    significant first), no parity, or, optionally, 7 data bits plus a
    parity bit, and ends it with 2 3/16 stop bits (logical 1, no
    pulse), and the bytes are asynchronous. IrDA differs a little in
    that it always uses 8 data bits and no parity, and transmits only
    one stop bit. For receiving, both SIR and IrDA require *at least*
    one stop bit, so the extra 1 3/16 stop bit from SIR would simply
    be ignored by IrDA.

    But note that, experimentally, the 49 series can use parity with
    its IrDA, just like the 48 series' SIR. I surmise that the parity
    is done "outside" of all IrDA layers, so the IrDA part simply
    treats the 7 data bits plus 1 parity bit as being 8 data bits.

    Either SIR or IrDA can use all bytes from 0 through 255 (decimal),
    although other software used with them may treat certain bytes as
    "control codes" instead of "data bytes".

    So it looks to me as if, although there are differences, with a
    stronger IR signal from the 49 series (or higher IR sensitivity in
    the 48 series), and bypassing all of the IrDA layers except the
    physical layer, it would probably be possible to have a 49 series
    SIR that would work with the 48 series' SIR. Oh well, it seems
    that that's the price that we all have to pay to keep the
    educational community happy.

    > Doesn't the ARM package come with built-in serial UARTs?


    Yes, three of them, and if I read correctly, they can be
    individually configured to invert the signal and set the pulse
    width to 3/16 bit time, as appropriate for an IrDA signal.

    I suppose that one UART could be used for wired serial (preferably
    with an RS-232 level shifter inside of the calculator), a second
    for IrDA, and the last with external circuitry to make the signal
    even more like the 48 series' IrDA. But as demonstrated in the 48
    series, as long as only one external I/O port is used at a time,
    only one UART is really needed, switching which additional
    circuitry is used as appropriate. So a serial port at the 0V/3.3V
    signal level could be used in addition to a real RS-232 port, just
    in case anyone really wanted it. But hey, any of that would cost a
    little more, so might reduce either sales or profits.

    >> the 49 series have both a reduced IR sensitivity and
    >> a reduced IR transmitting level, while the 48 series have only a
    >> even more reduced IR sensitivity, all to assure the educational
    >> community that the IR capabilities won't be used for surreptitious
    >> communications. It may be possible to overcome these restrictions
    >> with some hardware hacking, but I think that HP wouldn't
    >> appreciate anyone publicizing how to do that.

    >
    > In the HP48, changing some resistor allowed higher output power, IIRC.
    >
    >> I've tried using an INPRT program on a 48 to try to receive RedEye
    >> printing from a 49g+, but apparently the combination of low IR
    >> signal output on the 49g+ with low IR sensitivity on the 48
    >> prevented that from working.

    >
    > That's really sad news :-((


    Yes, I was disappointed.

    >
    >> Well, HP has made the details of the "RedEye" protocol available.
    >> Note that various other devices such as some medical and
    >> automotive test devices are designed to use the 82240 printers.

    >
    > Cool, where can I aim my printer to get my engine data? ;-)


    Search in the usual suspicious places for the printers, and you
    may find a test instrument set that includes (or can use) one of
    these HP or Martel printers.

    Some of the brand names that I've noticed use HP or Martel IR
    printers include Midtronics, OTC, Genisys, Telegan, Kane, Testo,
    Celltron, I-Stat, and Matco.

    >> Well, yes, IrDA is a good protocol, although much more complicated
    >> than the Serial IR communications or even the RedEye encoding
    >> which both came earlier.

    >
    > Again, is this about physical layer, or the other "IrDA stack" stuff?


    Well, the IrDA "physical layer" is no more complicated than SIR,
    but the mandatory IrLAP and IrLMP layers, as well as the optional
    additional layers and higher speeds, seem to make IrDA a lot more
    complicated than SIR.

    Of course RedEye encoding is a lot more complicated than SIR.

    >> [hpmuseum.org] understandably tends
    >> to be biased in favour of the "Classic RPN" models.

    >
    > They go well into the latter half of the last century:
    > "Some Interesting Later Models (1986)"


    I've noticed that, lately, the Museum Forum does seem to be more
    tolerant of RPL discussions.

    > But they do have one more final page:
    > "The Other Models"
    > http://www.hpmuseum.org/therest.htm
    > [where HP50G remains undiscovered :]
    >
    > Maybe it's like U.S. postage stamps --
    > any depicted person has to be long dead


    Well, the Museum is intended mostly for out-of-production models,
    but there have been plenty of discussions about the in-production
    "Classic RPN" 33S, so I figure that it should be okay to respond
    to posts about the 50g.

    --
    Regards,
    James


  12. Re: Questions about printing, printing and printing

    John H Meyers wrote:
    > On Sat, 14 Apr 2007 04:06:47 -0500, James M. Prange wrote:
    >
    >> But my understanding is that that program depends on a
    >> connection to a COM port, so how could it work it work with RedEye
    >> printing? It seems to me that to use it with any IR signal,
    >> hardware to convert it to an RS-232 compatible signal would be
    >> needed. Certainly it ought to work with an RS-232/IrDA converter
    >> and virtual COM port, or an RS-232/SIR converter,
    >> but where do we find an RS-232/RedEye converter?

    >
    > Some company (Aegis?) that sent me an evaluation sample of an SIR
    > receiver for potential HP48 use was evidently considering making one,
    > but I don't know whether they (or anyone else) ever did;


    I'd think that a reasonably skilled electronics hobbyist would
    find it easy enough to design and build a half-duplex "3-wire"
    2400bps RS-232/SIR converter. For the receiver section, take the
    pulse from an IR detector, and, assuming that it meets the minimum
    pulse width requirement, stretch it out to a full bit time, invert
    it if needed, and feed it an RS-232 level shifter. Optionally, if
    the pulse width exceeds the maximum allowable, signal a "break"
    condition. For the transmitter section, take the signal from the
    level-shifter, narrow the pulse width and, if needed, amplify the
    signal, and apply it to an IR LED ("IRED"?). Also, a
    transmit/receive switch may well be needed to prevent feedback;
    disable the receiver while transmitting.

    But how about an RS-232/RedEye converter? Instead of a 0 bit being
    simply the presence of an IR pulse and a 1 bit its absence, the
    signals are bursts of IR pulses, with the "start bit", logical 0,
    and logical 1 differing in which part(s) of the bit time the burst
    occurs. Each frame consists of 3 half-bit times each starting with
    a burst for a "start bit", followed by the 4 error correction
    bits, followed by the 8 data bits, with each error correction and
    data bit having a burst at the beginning of either its first or
    second half-bit time, followed by a delay of at least 3 half-bit
    times with no bursts. Unlike RS-232 (and SIR), the bits are
    transferred most significant first. It's easier (at least for me)
    to think of each byte as being encoded within a 30-half-bit frame,
    with 3 half-bits for the "start signal", 8 for the error
    correction bits, 16 for the data bits, and (at least) 3 with no
    bursts for a "stop signal". After converting a frame to 4 error
    correction bits plus 8 data bits, using the error correction bits
    for detecting errors should be straight-forward enough, but in
    case of an error, determining a correction or deciding that the
    byte is invalid seems more complicated. Well, for receiving, I
    suppose that one could simply ignore the error correction bits and
    assume that the data bits are correct, but the error correction
    bits have to be encoded (straight-forward enough) for transmitting
    to anything that expects a proper RedEye signal. With the data
    rates and encoding being so different, I'd think that a buffer
    would be needed. Certainly it can be done, but it strikes me as
    rather more complicated than an RS-232/SIR converter.

    > if this protocol was so popular for medical or automotive readouts,


    The ones that I'm aware of send the RedEye-encoded signal for the
    printers.

    Other than the HP and Martel printers and a 48 running an INPRT
    program, I'm not aware of anything that receives the RedEye
    signal.

    I'm not aware of anything else that uses the SIR signal as
    implemented on the HP 48 series, although as noted in my other
    post, IrDA's "physical layer" may be close enough, if one can
    separate it from the other IrDA layers.

    > that could have inspired some alternate PC-based solutions
    > (or even alternate mobile computing device solutions -- did
    > HP95/100/200LX ever handle it?)
    >
    > The internals of the printer do it (both HP's printer and Martel's),
    > so maybe there's a way to add an extra serial port to one of
    > those printers, the way HP has added an extra serial port
    > to an HP50, and use a printer itself as a converter for computers


    Yes, it has occurred to me that these printers do decode the
    RedEye signal to bytes, and presumably, it should be possible to
    read out these bytes from a printer's input buffer and convert
    them to whatever signal was desired. Maybe someone has a printer
    with a mechanical problem or a burnt-out dot in the print-head
    that he'd be willing to sacrifice for experimental purposes?

    > I wonder whether a TV "learning remote" can learn all the codes?
    >
    > Are there any cellphone/PDAs that can also "learn" IR remote control codes?


    Perhaps, but I don't own any of those.

    > (interesting possibilities there -- after all, there have been
    > "TV learning remote" programs which run on an HP48!)


    I wonder how those programs would treat a RedEye signal from
    another calculator.

    > Apparently there do exist "raw" IR receivers which go into
    > serial/USB ports, and in that case, PC software could take over
    > the responsibility to decode it. The possibilities are staggering
    >
    >> I've read of these boosters, as well as boosters that don't slip
    >> onto a remote but are placed elsewhere, with the intention being
    >> to boost the signal enough that it could find its way (via
    >> reflections) around obstacles, into other rooms (assuming an open
    >> door), and so on. It seems to me that something like that might
    >> work with the calculators.


    Looking again, what seem to be most readily available are devices
    that receive an IR signal, transfer it via wire or RF to another
    location, and then transmit the re-created IR signal from there.

    It occurs to me that there may be a feedback problem if the IR
    receiver is within range of the IR transmitter, rather like the
    squealing that occurs with an audio amplifier when a microphone is
    too close to a speaker.

    >> I'd think that such a device would be obvious enough for educators
    >> and test proctors to easily notice. What would be more of a
    >> concern would be internal hardware modifications to boost the IR
    >> signal power or sensitivity.
    >>
    >> But hey, with so many students carrying cell phones and
    >> Wi-Fi-capable hand-held game gadgets, why would they bother trying
    >> to use a calculator for communications?

    >
    > "Because it's there"


    Good point; I always found it difficult to resist finding new ways
    around the teacher's rules.

    > Have you tried an external lens yet, to focus the IR beam better?
    > (the Brinkmann LED flashlight I'm holding has a lens in front
    > of its one LED and reflector, and that lens does focus the light
    > into a narrow spot -- all we need is to be sure the lens material
    > passes IR very well.


    Now that's an interesting idea. The magnifiers that I have readily
    available seem to be reasonably transparent to the IR signal. But,
    short of having an IR imaging device, how to determine when it's
    focused? Would focusing an ordinary red LED determine it close
    enough, or would it be necessary to apply some formula for the
    difference in the refraction at the different wavelengths? Of
    course, a "trial and error" method is always a possibility.

    > So I guess I wasn't thinking about decoding the "Redeye" IR in the computer,
    > but look at all the possibilities that you've meanwhile uncovered


    All very interesting, but I can manage to transfer from any of my
    28/48/49 series to any of my 48/49 series, although sometimes it
    requires my PC as a go-between, and in the case of transfers from
    a 28 series, a 48 series running an INPRT program. None of these
    experiments are very near the top of my to-do list.

    --
    Regards,
    James


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