Re: replacing 49g+ Message #10 Posted by James M. Prange (Michigan) on 16 June 2006, 11:20 p.m., in response to message #9 by declan
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.
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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.
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Maybe I'm just getting old.
Well, we're all getting older. That does seem much better than the
available alternative.
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The feel of the 49 compared to the 48 is crap,
I agree.
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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
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