replacing 49g+



#2

I have been using programmibles since a TI-59 in mid seventies. (Maybe I should say that it really began with my K&E Decilog in the sixties). Early interest began with curiosity about financial calculations and jumped forward to optimumization problems involving queing theory and learning curves in the computer service industry. Subsequent pockets have been served by hp products, mostly RPN. (28, 12, 18, 15, 48s and 49g+. I have programmed such things as IRR from uneven transaction dates and/or amounts, fixed and variable rates for cash manager's short term investments, in other words stuff not available in earlier units, some still not available. I have wondered why, for example, did it take so long for the natural log of 1+x to show up for compound interest or why it still isn't evident that simpler calculations like continuous compounding of estimated cash flows yields calculations more accurate than the guestimates of the cash amounts or timing.

Anyway, to the point, I lost my 49g+ of two years - it just went blank and change of batteries did nothing to restore. I removed my memory card and tried all the self testing codes beginning with the warm start code. Looks pretty broken unless there is a reset of some kind I am missing. I gave away my 48GX and have to retreat to an SX for now. This looks like a good opportunity to get out of the 49 for something that both serves and recognizes that my laptop with software like Mathcad and Excel handles the real heavy stuff on the move. I see where there is something new going on in Cupertino/San Jose this year. Think I should wait? Different voices suggest at least a prototype by fall.

I welcome this opportunity to consider getting out of the 48/49 system for a couple of reasons. The 49g+ is too general and tries to do so much that I sometimes get lost. Those flimsy keys! It just doesn't FEEL like an HP!

As Indicated above, I don't tend to be limited by the calculators built-in operations versus its room to use basic fundamentals in routines I develop for myself. For that reason alone, I would need programming support in the unit, like flash cards and some way to change firmware. The unit I buy next should have plenty of data entry support from key input to media transfer via USB and other methods, handle all conventional matrix and vector routines and be updated to handle current level of differential equations at least to the level of Mathcad 13. It has been discouraging trying to obey the syntax rules for entering DEQs in the 49. I would hope that most basic calculus will return exact-symbolic solutions and have graphic support for those that must be numeric solutions. I have enjoyed the CAS choices in the 49.

Should I wait for the new one or start looking more seriousl at some of the 3x models?

Thanks for your input,

Ron


#3

On the 49g+, there can be a problem with the AAA cells not making
contact at the positive post, particularly at the top cell. It
depends on the diameter and length of the positive "button" on the
cell, which varies among manufacturers.

Other than that, have you tried a hardware ("paperclip") reset?

It seems that we can expect a new HP model (50g) soon; see
http://commerce.hpcalc.org/, and recent discussions of it in
this forum and in the usenet group comp.sys.hp48.

Regards,
James


#4

Thanks, James. None of that worked at this point. I have replaced two sets of Duracells from separate packs and punched the reset several times.

Thanks also for the lead on the 50g. I'll see if there is any press on it.

Ron


#5

As far as I recall, Duracells are the ones usually mentioned as not making contact. Maybe try a different brand, such as Energizers.

Regards,
James


#6

Tried new energizers and the circut discharge trick to no avail. It wasn't clear if "left-to-right" meant from the open rear plate or the lcd panel. I assume you meant across the battery compartment from ground to plus serially - only one that makes sense.

I then tried to reset again with the paper clip. I did notice that with batteries in, I get a horizontal line advancing to about three different places each time I push on the paper clip. I would describe the Lines as meaning a vertical deflection circuit failure if the LCD panel was the face of a CRT.

I located my 48GX (didn't give it away after all). As much as some of us enjoy a chance to trouble shoot now and then, who has the time when an acceptable backup is available? I now have a "reason" to wait for the 50g to be available before going to another hp calc.

Frankly, it feels good to have that old HP feel when I use the 48GX. Reminds me of a burglary some time ago. I lost my old Nikon that had traveled the world with me. The insurance company replaced all my equipment with current replacement value, but even the "F" series electronics didn't have the "feel" of the newer units, I even felt unfathful when I enjoyed the results of my new F-5. I made the adjustment however, but Nikon had remained faithful to me, keeping their end of the bargain with the glass I expected and improved the ruggedness of a professional camera. I hate to admit it, but HP has cut too many corners with the 49g+. I appreciate the effort to give me more features for the same price. I think I would be willing to pay a little more for the old "feel" of the keyboard and for them to quit trying to compete with TI and CASIO in color schemes. I like the basic black and Mercedes-tyoe aloofness in design.


#7

Were you referring to my post when you mentioned the "battery discharge trick? If so I meant right and left as you view the calc face-down but I think you've probably already gathered that. Sorry it didn't work for you but I hope someone else can help.

Best regards
Declan


#8

Thanks for your assistance, Declan

Do you happen to know how to locate the version of my 48GX, now that I have it back in my briefcase? Don't go to any trouble if you don't, I should be able to do the research - just can't find it in the documentation.

Thanks again for your efforts,

Ron

#9

Sorry to read that nothing has revived your 49g+.

The shorting out method would indeed mean from your lower left to
upper right as you face the open battery compartment; the other
four contacts merely connect the AAA cells in series.

It could be that some glitch has locked something up in an
abnormal state, or of course it could be that some hardware
component has failed permanently.

I don't know for sure, but it may be that a capacitor is prevented
from discharging completely by the electronics. Maybe try removing
all cells, including the lithium coins cell, for a few days.

The horizontal line on the LCD when doing the paperclip reset is
normal, but normally it would do a warmstart when the paperclip is
removed. It does at least show that your AAA cells were all making
contact correctly.

I'm glad to read that you found your 48GX. Don't get rid of it;
that one's a real "keeper". Personally, I like to play around with
the 49 series, but when I just want to get something done, I
prefer the 48 series.

Regarding the 50g, we don't know much about it yet. As far as I
know, HP hasn't publicly announced it yet, although "HP authorized
dealers" know at least something about it. I certainly hope that
it will be an improvement from the 49g+, particularly the keyboard
and improved I/O capabilities. But experience with the 49 series
may well be regarded as reason not to buy the 50g, at least not
immediately, unless you just want to have the "latest and
greatest" gadget. No doubt there will be reviews of it at
comp.sys.hp48 before too long.

Regards,
James


#10

Can you switch easily between the HP49G+ and the HP48GX? I haven't completely got used to the 49 key layout but when I go back to the 48 (because I need to use the RS232 to talk to instruments) I feel completely lost! Maybe I'm just getting old.

The feel of the 49 compared to the 48 is crap, but it's much faster with lots of storage so for the RS232 I think I'll have to buy a 50G - but I'll try to take your advice and wait for other buyers to comment on it first.

Best regards
Declan


#11

Quote:
Can you switch easily between the HP49G+ and the HP48GX?

For the most part, yes. When using a 49 series, I do have to
remind myself to "just press firmly" to get the keystrokes to
register reliably, and I often get confused by the ENTER key being
in the wrong place. I suppose that if I switched to using the 49
series exclusively, I'd get used to the placement of the ENTER
key, and I just might even develop a habit of pressing extra hard.
The menu arrangement of the 49 series doesn't seem as good as on
the 48 series, but I've found that it's often faster and easier to
simply key in command names, even on the 48 series.
Quote:
I haven't completely got used to the 49 key layout but when I go
back to the 48 (because I need to use the RS232 to talk to
instruments) I feel completely lost!

To be sure, as the keys are rearranged, I do have to actually
look at the keyboard, rather than relying on memory. But even with
just the 48SX and 48GX, I had to look at the keyboard for the
"shifted" keys.

Regarding RS-232 compatibility, the 49G does have it, although
XON/XOFF software flow control doesn't work with the 49 series.

The 48gII has almost RS-232 compatible I/O. From what I
understand, its signal levels are 3.3V/0V at the calculator port
itself, and it relies on a level-switcher built in to the cable to
get them to RS-232 levels. The level switching hardware relies on
being able to "steal" power from other lines in a 9-pin port, so
it may not work with your instruments, although by all reports
that I've seen, it does work with a standard COM port on a PC. One
could, at least in theory, make an externally-powered adapter to
go between the 48gII's cable and the other RS-232 device, to
supply the power for the level-switcher.

There may be a possibility of using an RS-232/IrDA converter with
your instruments, but even that may rely on "stealing" power from
lines other than "Transmit Data" and "Receive Data", or on
supplying external power.

Quote:
Maybe I'm just getting old.

Well, we're all getting older. That does seem much better than the
available alternative.
Quote:
The feel of the 49 compared to the 48 is crap,

I agree.
Quote:
but it's much faster

Perhaps so (for the 49g+, anyway), but for most of what I use a
calculator for, the 48 series is plenty fast. If a program takes a
few seconds instead of a fraction of a second to run, that gives
me time to pick up my pencil. Of course, when a program take
"several" seconds (or minutes, hours, etc.) to run, the extra
speed is appreciated.

And perhaps speed should be judged on overall problem-solving
"throughput", including correcting problems from keystrokes not
being registered properly, dealing with "unexpected" results due
to the CAS, and so on. Of course this is rather subjective.

Quote:
with lots of storage

Well, the 48GX comes with a lot of storage capability built-in,
and you can always add a RAM card. For relatively low-cost 48
series RAM cards, see
http://stores.ebay.com/Klotz-electronic.

But I'll grant that the 49g+'s MMC / SD card is a big advantage,
although it stores objects as binary-transferred files and isn't
the same as a 48 series "port". As far as I know, the smallest MMC
/ SD cards made were 8MB, about double the largest RAM card that a
48GX can use.

Quote:
so for the RS232 I think I'll have to buy a 50G - but I'll try to
take your advice and wait for other buyers to comment on it first.

The DynaTech Site does seem to indicate that we can expect RS-232
compatibility, but will the signal levels be RS-232 compatible
(like the 48 series and 49G) or will they need external power for
a level-shifter (like the 48gII)?

For me, what I've read of the 50g so far is indeed very tempting,
especially if Eric's $130 price is correct. I'm looking forward to
reading what HP itself says about the 50g.

So far, I haven't seen anything "official" from HP. Perhaps they
don't have a supply of them ready for shipment yet, or perhaps
they want to sell off some of the remaining stock of the 48gII and
49g+ before announcing a replacement.

Regards,
James


#12

I've thought about an RS232-IRDA converter - but that's as far as I've got - just thinking about it. It would be quite neat but if the 50G is good then that will solve the problem.

The SD storage and extra speed has made a big difference to the way I use the calc. I used to write and tweak programs to be as small as posible which meant if I came back to them a year later I had a lot of trouble figuring out how they worked. My programs are now getting bigger, but modular and more understandable, stored in the SD card but still run faster! I carry around lots of data and I don't have to worry about rewriting it to save space.

My 1GB SD card cost less than the 1MB card for the 48GX. 1GB is completely over the top but it means I never worry about storage - I carry around loads of downloaded programs that I can try out in an idle moment.

The downside is it might make you less disciplined and code inefficient - but that's probably the way of the world these days.

Thanks for your reply
Declan


#13

Quote:
I've thought about an RS232-IRDA converter - but that's as far as
I've got - just thinking about it. It would be quite neat but if
the 50G is good then that will solve the problem.

Yes, assuming that you may be willing to spend the money for a
50g, I'd think it better to wait and see how (and, for that
matter, if) it implements RS-232 compatible I/O. You may still
have to find a way to supply power to a level-shifter, but I'd
think that better than using an RS-232/IrDA converter, which you
may also have to find a way to supply power to.

Quote:
The SD storage and extra speed has made a big difference to the
way I use the calc. I used to write and tweak programs to be as
small as posible which meant if I came back to them a year later I
had a lot of trouble figuring out how they worked. My programs
are now getting bigger, but modular and more understandable,
stored in the SD card but still run faster! I carry around lots
of data and I don't have to worry about rewriting it to save
space.

Yes, you can choose to "optimize" programs for various goals, such
as speed, size, clarity, or some combination of them.

Of course "clarity" depends a lot on who's trying to understand
the program. Note that if you write your programs on a PC, you can
format and comment them as you like. Well actually, you could do
this on the calculator, but the formatting and comments are
discarded by the compiler. If you want to preserve any formatting
and commenting, then write the program within a string, and then
use STR\-> to compile it. But if STR\-> results in an "Invalid
Syntax" error, it won't give you any hint as to where there error
is; in this case, edit the " delimiters out and press ENTER.

Quote:
My 1GB SD card cost less than the 1MB card for the 48GX.

Quite so; the lower price, larger capacity, non-volatility, and
availability of card readers were what I had in mind as advantages
of these cards. I don't think that anyone would want to go back to
proprietary and expensive cards for our calculators now that
better solutions are available.

Note that you can't attach a library stored in "port 3", because
it's really stored as a binary transferred file, but the other
ports seem to provide plenty of capacity for storing libraries.

Quote:
1GB is completely over the top but it means I never worry about
storage - I carry around loads of downloaded programs that I can
try out in an idle moment.

The downside is it might make you less disciplined and code
inefficient - but that's probably the way of the world these days.


Judging from PC applications, software does seem to bloat to use
up the available hardware capabilities. We do see the same in the
calculators; more capabilities, but more storage capacity used up
too.

Regards,
James


#14

Thanks as ever for the comprehensive reply - I think I'll try to shut up for now until an HP50G is available. This could be some time because HP calcs have a very very low profile in the UK - and they're very expensive - I've bought all but my first HP calc overseas.

Interstingly I don't think any of us answered Ron's original question - where to go after the HP49G+. PDAs and suchlike are over the top with a cumbersome interface and don't allow quick and dirty programming, leaving us to dream of something like the QONOS or even HPs Xpander.

Best regards
Declan

#15

Thanks again for trying to help me, James. Your efforts were obvious to me and I just want you to know how much I appreciate it. I wrote a similar posting a couple of days back, but it seems that I didn't get it posted right.

If you know the answer to this question please post it for me, otherwise I should be able to do the research for myself:

Question - How do I find the version number for my 48GX? I have tried executing : VER, VERS, VERSION, RE;, REL, RELEASE, MEM, MEMORY, UTILITES, ETC AND CAN'T FIND IT IN THE MANUAL.

Thanks for even considering it,

Ron


#16

Try again with VERSION.

Regards,
James


#17

Must have spelled it wrong? Version worked this time! Thanks again. I'm sure there have been a few updates since HP48-R, 1993. Maybe I can locate a copy since they probably don't support it this late.


#18

According to http://www.hpcalc.org/hp48/docs/faq/48faq-3.html, you already have the latest (and presumably last!) ROM version.

- Thomas


#19

Thanks for the FAQ on the 48 series - helpfull,

Ron

#20

As Thomas says, you probably have the latest ROM which is lucky as you can't upgrade the 48 series. Well, maybe you could if you attacked the calc with a soldering iron and could program your own ROM.

If you bought an early calc with a really really bugy ROM then HP would replace the whole calc, but otherwise you were stuck. I can vaguely recall my first HP48SX having a really annoying bug - I think if you left the clock displayed while doing a backup it would crash instead - I can't think of a more frustrating bug than that!

Best regards
Declan

#21

Before you throw away your calc, try one of these:

Slow method - remove all batteries including the coin cell and leave for at least three days. I saw this method recommended by HP and it did work for me.

Quick method - One of my calcs often appeared to die and waiting three days each time would be ridiculous so I found a quicker fix. Remove the AAA cells (leave the middle one in place if you like). The coin cell can stay in place also. With a bit of wire or some keys etc. briefly short out the top right and bottom left battery contacts. Replace the batteries and switch on.

I must have done this about a hundred times and it doesn't appear to have caused any further damage. Surprisingly it never cleared or corrupted memory either.

I contemplated fitting a switch to break the battery circuit and short the contacts! But the calc has been behaving itself for several months now.

Good luck!
Declan


#22

Thanks much for the tip - exactly the kind of experience with an electronics gimmick. Knew there was an experienced techi out there.

Cheers

pS JUST THE ONE OBVIOUS QUESTION. Hundreds of times?? - I should be looking to move up to a 50g out of principle with that.


#23

Do take my opinion with a pinch of salt - but for what it's worth It seems that all complex electronics can be liable to very rare but unexpected lock-ups. I've just been unlucky that one of my HP49G+'s has probably got another fault that pushes it into this mode regularly.

With power-hungry devices you can switch them off and on - but with low power electronics a capacitor can hold just enough charge to keep it in this state which is probably why shorting out the battery contacts is quicker than just leaving the batteries out.

Many years ago My HP48SX did this, just once in its long life. I wouldn't expect the HP50G (or any calc from any manufacturer) to be any better or worse in this respect. It'll probably never happen - but it's nice to know there's a fix just in case.

Guess what? I just tried to switch my calc on and it wouldn't! The bloody thing must be reading my posts. The "quick fix" worked but I'm going to get a HP50G as soon as it's available and teach it a lesson.

Best regards
Declan


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