HP 48 Calculators-Serial Numbers and Keyboards


Does anyone know which of the 48 style calculators have better keyboards (48s, 48sx, 48g, 48g+, 48gx) compared to early HP calculators? Did any of these 48's use molded keys or were they all made with painted on keys as is the current practice? It's interesting to read the HP Museum's list of Earliest Serial numbers. Does anyone know the year when each 48 was discontinued?

I prefer my 28s keyboard feel to many HP's I've used and owned (despite the clamshell design). Not sure how the 48 keyboards compare?


All the early S and SX models made in the USA had molded keys. Other 48 serial numbers that have an S in the fifth position were made in Singapore and should have molded keytops. There were a few that began with SG later in the life cycle, they had printed keys. ALL Indonesian machines had printed keys.

The Clamshell keyboard design was unique. While it was similar in concept to the 48, they were quite different internally. The Clamshell keyboard flex dome was only a dome, it had no conductive material. When you press, the dome deforms and ultimately the actuation pin of the key forces two conductive sheets together. In the 48 and Pioneer machines, the flex dome has conductive material inside. Flex and deform the dome far enough and the conductive material touches a grid underneath, making the cross point.


I didn't think any of the 48's were made in the good old USA.

I know HP shifted to the different (IMHO Harder to read) colors with the 48g. Is this shift to the new colors when they also dropped the molded keys (ie. do any of the 48g series have molded keys)?


I have a 48SX with a serial 3107Axxxxx, and another with serial 3117Sxxxxx, so the manufacturing move was someone between them.

I believe the older 48G series have molded keys. The newest (Indonesia manufatured) one I have has slightly different printing on the keys from my older (Singapore manufactured) ones.



My 48G with serial 3425Sxxxxx definitely has molded key legends. So the switch to the new colors on the 48G did NOT coincide with the move away from molded keys.



I have four 48G series:

48G Singapore, molded double-shot keys

48GX, Singapore, molded double-shot keys,

48GX, Singapore, molded double-shot keys, SN 3507S02514

48 GX, Indonesia, Painted Keys

(I only have the one in front of me).

The Singapore in near new condition (the 3rd in the list) has the best keys wothout a doubt. The Indonesian has a different feel--a bit easier pushing. The other Singapore GX shows some definite differences between one key and the next--sone are crisp like the near new one, and others are rather softer--the end-snap is not as pronounced.

The indonesian keys are all same feeling--except the ENTER key which has broken one of its hinges :--((.

So, wear and tear is important. I would say that with teh exception of the broken ENTER key, my Indonesian unit (which shows lots of use) ages more gracefully than the heavily used singapore. Of course, this is only the story of 4 particular calculators!


What're your preferences for the color schemes for the 48's? Do you prefer the look of the 48g or the 48s?


The 48G was my first HP, so that is the one I prefer. I find the 48s so boring to look at (kind of lost in the 80s).
However, I guess most of the readers here prefer the serious colours of the 48s



I guess I'd call the 48SX color scheme white primary labels on the
keys themselves, with orange and medium blue for the shifted labels,
on a dark brown background.

For the 48GX, the primary labels on the keys themselves are still
white, but the shifted labels are sort of medium purple and medium
blue-green on a dark blue-green background.

Yes, I know there are special names for the colors, but I never did
find much use for all of the 16 colors in my Crayola box.

I suppose that some might consider the 48GX color scheme to be more
"aesthetically pleasing", but what matters to me is how easy it is to
read the labels, and the 48SX is definitely easier. With the 48GX, the
purple labels in particular don't contrast enough with the background.

I don't need a calculator to be pretty, I just need it to be useful.
Offhand, something like white, fluorescent orange, and neon blue on a
black background might be my first try for a functional color scheme.
Or maybe white, black, and neon blue on a fluorescent orange
background? Well, I guess I'd settle on good contrast, but not
dazzling colors or contrasts, which I suppose describes the 48SX
pretty well.

But I wouldn't decide based on the colors alone. After all, once
you've become accustomed to a particular calculator, you pretty much
know where the keys are, even without carefully reading their labels.

The 48GX is noticeably faster than the 48SX.

The 48GX has better display contrast than at least most 48SXes. I
believe that the improved display was added near the end of 48SX
production. I've read that very late model 48G series have an even
higher contrast display, but haven't actually seen one.

Some functional improvements to the EquationWriter were made near the
end of 48SX production, most noticeably to backspacing (painfully slow
on my 48SXes), and I believe improvements to plotting and solving
speed too. These are in the last ROM version, J, of the 48S series. Of
course they're also in the 48G series, which started with ROM version
K. If you intend to use these much, the 48GX may be the better choice.

The 48GX has 128KB RAM built-in, compared to the 48SX's 32KB, and in
slot 2 it can take up to almost 4MB compared to the 48SX's maximum
128KB there. On the other hand, with the 48SX you can merge the RAM
from both slots with system RAM, but with the 48GX, only the RAM in
slot 1 can be merged with system RAM, so the maximum merged system RAM
on a 48GX is about 32KB less than on a 48SX.

The 48GX has both a flag browser and a character browser which the
48SX lacks; I find them useful.

The 48GX has what they call "parallel" processing with lists.
Basically, use each element of a list as an argument and return a
list, or with matching list sizes, use corresponding elements from the
lists as arguments. Also there are commands for summing or multiplying
all elements of a list. It does save some steps in a program, but
"parallel" is perhaps inaccurate; I find it at least as fast (when
executing the program) to use a loop to process list elements and
accomplish the same things, which I believe is exactly what the
so-called parallel list processing really does.

Most of the 48SX equation library, an add-on ROM card, is built-in
with the 48GX, but not the periodic table. Later versions of the
equation library ROM card have a Tetris game, which also didn't make
it into the 48GX ROM.

The 48G series has several new commands. For me, perhaps most useful
are the commands for inserting, deleting, or re-arranging rows or
columns in matrices.

The 48G series has several built-in input forms (on right-shifted
keys), perhaps useful when several parameters have to be set for what
you what to do, but I sometimes find them more of a hindrance than a
help. The regular menus are on the left-shifted keys.

Most UserRPL programs for the 48S series (and even the 28 series) work
just fine on the 48G series. One thing to watch for are global names
that match command names on the newer calculator. Another thing is
would be that some commands, particularly with the 48G series'
enhanced list processing, actually behave a little differently.

Libraries and SysRPL programs for one series may or may not work on
the other, due to some changes in the entry points and a different
memory management scheme.

Overall, I've come to prefer the 48GX to the 48SX, but I do think that
they took a few steps in the wrong direction too.

But I expect that anything I've ever done on a 48GX I could also
accomplish on a 48SX, although sometimes using more steps and ending
up with a bigger and slower program.

Perhaps the biggest problem for me is switching back and forth among
the various calculators. I have the 28C, 28S, 48SX, 48GX, 49G, and
49g+, and although they do have a lot in common, they're different
enough that I have to think about where the various keys and menus are
on the particular calculator that I happen to be using, and which
commands are available with it.

Oh, I have a 16C too, but I use that only for working with "binary"
integers, and even for that, the RPL calculators usually suffice for
my purposes.


Possibly Related Threads...
Thread Author Replies Views Last Post
  HP Prime: complex numbers in CAS. Alberto Candel 1 842 12-06-2013, 02:36 PM
Last Post: parisse
  [HP Prime] Plots containing complex numbers bug? Chris Pem10 7 1,691 12-05-2013, 07:40 AM
Last Post: cyrille de Brébisson
  DIY HP 30b WP 34s serial flash/programming cable Richard Wahl 2 1,139 12-04-2013, 11:14 AM
Last Post: Barry Mead
  HP PRIME: command to read the SERIAL ? Joseph Ec 9 2,706 11-01-2013, 12:43 AM
Last Post: Joe Horn
  comparing numbers on the WP 34S Kiyoshi Akima 7 1,394 10-19-2013, 09:28 AM
Last Post: walter b
  HP Prime: Operations with Large Numbers Eddie W. Shore 0 478 10-19-2013, 12:24 AM
Last Post: Eddie W. Shore
  HHC 2013 room numbers David Hayden 2 735 09-20-2013, 05:34 PM
Last Post: sjthomas
  [HP-Prime xcas] operations with complex numbers + BUGs + Request CompSystems 9 1,662 09-08-2013, 10:40 PM
Last Post: CompSystems
  TED Talk: Adam Spencer: Why I fell in love with monster prime numbers Les Bell 3 865 09-05-2013, 12:54 PM
Last Post: Ken Shaw
  Oldest HP 41c aka earliest Serial Number Gene Wright 23 2,845 09-05-2013, 03:45 AM
Last Post: Geoff Quickfall

Forum Jump: