HP 48GII and 49G+


Hey folks,
I am a bit confused as to why HP decided to build both the 48GII and 49G+. The calcs seem identical except that the 49g+ includes:
1. More memory
2. Flash ROM
3. Bigger LCD
4. SD card slot
5. USB vs. serial port
6. Gaudy gold vs. nice silver color (IMHO)

Okay, what gives? It seems that the two calcs overlap each other. What was the point in even building the 48gII other than to give the machine a serial connetion? Also, why leave out the flash ROM on the 48GII? If there are any bugs in the machines, what can possibly be done to fix the problem?
I would love to hear everyone's opinions on this.
Oh, I am looking at getting an HP graphing calc to accompany my TI 89 (and HP 33s!!!). Should I go with the 49g+, 48gII or the older 49g?
I met another student who uses the older HP 49g. I played with it and (suprisingly) I liked the keyboard and rubber keys on it better than the 49g+ I bought last November...which I returned the same day thanks to the crappy keyboard. Has there been an improvment in the keyboard of the new 48/49 models? Also, if I go with the older 49g is there any "gotchas" I need to know about? Thanks for all the help in advance.



I to feel Hp is making some design mistakes with the 48GII, but at the price they offer it, it looks to be a very good buy. Especially if you subject a graphics calculator to extreme use and do not need to modify it too much.

I feel Hp should have named this something else, but marketing doesn't want to call it what it is, a 49G minus. While it is probably faster than the original 49G, it lacks memory and a true RS232 port. But Hp has improved the keyboard ie same as the 49G+ and it does look better than anything except perhaps the Hp39G+ ( I haven't seen either in person, but the dark blue of the old 39/40G was much better than the FHB (ice???) Blue of the original Hp49G).

The flash rom you mention has already cost HP millions because the Hp48GII was released about the same time as the Hp49G+ and had the same battery drain bug, which could not be corrected, so Hp had to pull the 48GII from distribution. And since none of the new calculators are actually repairable or flashable, probably all were destroyed.


Hi Ron,

Can you elaborate on the RS-232? You say it is not a "true" rs-232. How does it differ from (a) 48GX and (b) any old laptop RS-232?




It provides no power, it has to ride along or piggy back onto a true RS232 device. But it cannot control any devices as it is presently made (most controled devices require the master to supply the voltage on the cable). Its cable has to rob the 5 volts (actually 3.3 or so works) from the PC to work. Therefore it isn't as versatile as a 48G or older 49G in this regard either. Works great hooked up to a PC, but cannot really tie into data acq systems unless you provide a 5 volt supply and splice into cable.

Nice isn't it? Hp worries about battery drain from the RS232 port, but leaves a bug in the OS (originally).


I'll bet the hardware guy that did the 232 implementation, probably cutting it down against his better judgement, was truly pissed when he discovered that the software people had porked the O/S.



Probably saved 30-50 cents per unit by skimping on the serial port. I understand another 50-80 cents is saved by not having flash ROM.

Total savings to cost $1-1.50. I am sure we are all happy they can pass that cost to us.

Of course a few dollars were lost when they could not upgrade the ROM since the OS had an error that caused a battery drain.


About 2 years ago I bought a 48GX for $35. I inquired about the price. Office Depot told me that they were getting rid of all of their HP calculator at their cost (what they paid for them). If you work the math backward from retailer to wholesaler/distributor to manufacturer and each doubled (2X) there price as they moved forward from the manufacturer. It only cost the manufacturer about $5 to make the 48GX.

Think about it. The retailer was selling it to us for about $120 and it cost the manufacturer $5 to make in (X) number of volume. A $1.50 more might have cut too far into the manufacturers profits to put a fully functioning RS-232 port in the 48GII.


"was truly pissed when he discovered that the software people had porked the O/S."

The Software people were truly pissed when they discovered that the Samsung's hardware people had porked the CPU pins (changed from the original design announced before the 48gII project).



Well, no doubt they were. But if you were making a new product,
wouldn't you do very thorough testing on the first units from your new
production? I can sympathize with the problem of having a supplier
make undocumented changes, but not with the problem of letting
defective units from a new manufacturing process actually getting
out to the market.



Actually, the 48 series and 49G don't comply with RS-232 either. Their
output is about +/- 3.5V, possibly as low as +/-3.0V; see:
http://www.hpcalc.org/details.php?id=4741. To meet RS-232, the
transmitted signal would have to be at least +/-5.0V. But RS-232
specifies input levels of +/-3.0V, and the calculators are usually
used with short cables with little signal loss, so it's probably fair
to say that they're "RS-232 compatible". I think the manuals never
actually claim this, calling it a "serial port" instead. The only
problems I recall reading about were with some Macs, which I expect
were actually equipped with RS-422 ports instead of RS-232 ports.

My understanding is that the 48gII signal level without the special
cable is practically identical to the 48 series and 49G, so if you
supply your own non-amplifying cable, you can probably use it wherever
the older calculators would work.

Regarding the lack of an upgradable flash ROM, yes, it seems foolish
to expect to get a reasonably bug-free ROM, especially in a hurry with
practically the same complicated ROM used in the 49 series and the
processor emulated. What were they thinking?

And it has less RAM available than the 48 series, and no expansion
card capability. Too expensive for a "low-cost" model in my opinion. I
wonder who would buy it; it's hard for me to imagine the niche in the
market that it fits into. But who knows? I'm no marketing specialist.

Still having an RS-232 compatible serial port does sound good though.

The USB port on the 49g+ is nice, but I'd much rather they'd added a
USB port and kept the RS-232 compatible port instead of replacing it.


Edited: 29 Apr 2004, 8:42 a.m.


To elaborate on what Ron mentioned, see the following Post "
48GII RS-232C problems solved" from comp.sys.hp48.

Here's a quote from the author of the post, Bob Roberts (October 30, 2003):

"Took one for the team. My suspicions were realized as I cut open the molded plastic cover on the D-sub end of my brand new (now non-returnable) 48GII cable and dug through the potting material to see active components hidden underneath. Looks like (in order to save cost/power???), HP decided not to include a functioning RS-232 port on
the unit itself. Instead, they have included the RS-232 transceivers in the custom cable they supply with each unit. They simply drive the logic levels of the uP UART out of the connector on the back of the unit. The active components within the cable then convert the logic levels to RS-232 signal levels. Problem is they did not supply the
power necessary to drive these active components. Instead, they are stealing power from the modem control lines of the RS-232. This is fine as long as you 1) use the supplied cable, 2) don't use an additional cable extender that does not support the modem control lines and 3) connect your 48GII to a PC using HP's driver software which will toggle either the DTR or RTS lines of the PC to the proper

"If you are attempting to connect the 48GII to any other RS-232 device you will need to make sure that it can supply the signals necessary to power the cable circuitry. This will probably include making sure it supports the modem control lines (many current RS-232 devices do not) and making sure the device's firmware/software drivers keep the modem control signals in a state that keep the cable powered properly. This may require a rewrite of the device's serial drivers. In some cases (such as a modem that uses these lines for it's operational functionality), you may be out of luck.


Hope that helps,



Hi Matt,

It does help--it basically says that we are SOL here!




TDS website www.tdsway.com has a handheld device called a RECON that has both USB and serial ports in the same unit. HP should have both serial and USB ports in their next graphing calculator. It could be called the HP 49GX or HP 49GX+. There would then be no need for a separate graphing calculator to succeed the HP 48GII.



thanks for your link, www.tdsway.com .

It seems that they aught to be building our favorite calculators, instead of Kinpo/hp!

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