HP 48 SX or GX

[Joe Edwards]

Hey folks,
I am in the market for another calc. and I would like to buy a 48 *x model. I currently have a 49g (old model) which I love (except for the creaky case).
I have played with the the 48g models, but what I want to know is what are the differences between the 48 S/GX models besides memory. Speed? Does the SX run all the expansion cards that the GX does? Also, what is the largest memory card the SX can hold.
Why do I even ask? Price and I have heard some folks say they prefer the SX model. Keyboard layout? Construction quality?
Thanks in advance.

Joe

[Raymond Del Tondo]

Hi,

I'd go for the GX, of course. Almost all things are better in the GX compared to the SX, the most important points are the much better display, the speed increase, and the 128K of built-in RAM (the SX has only 32K).

For the display, take a look into this thread:
http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/forum.cgi?read=56518

There you'll have a direct side-by-side comparison of the 3 different displays used in the HP-48 series.
Seen from today, the SX display is absolutely the worst possible.

The only drawback for some people is the color schema of the GX, but hey, nearly every other HP calc has a better and more ergonomic color schema than the 49g (blue & red letters on 'metallic' blue...;-)

In most cases, expansion cards are interchangeable between the SX and GX, but there are some cards, mostly preprogrammed software, which are made for the SX or GX specifially.

There were so-called multi-memory cards (multiple bankswitched 128K blocks) for the HP-48SX from TDS (e.g. 256K), I don't know which one was the largest, I assume that you can use up to two multi-memory cards in the SX at the same time, so you had a maximum of 512K independent memory, and the 32K main memory.

There were (and still are) also various RAM cards for the GX, theoretically up to 4MB, but due to an addressing bug in the 48GX ROM to a max of 2MB. These cards can only be used in port 2 of the GX, wheras only 32K or 128K cards can be used in port 1 .

Theoretically you can use the TDS multi-memory cards in port 1 of the GX, but IMHO it doesn't make too much sense, because I doubt you'll ever need that much memory. Apart from that, you'd have to write your own driver software for the bank swwitching in ML, because I'm sure the TDS drivers won't work in the GX.

Summary: Forget the SX, go for a GX, preferably for a unit with the black&white display of the 49g.

HTH

Raymond

[marais]

I own both and prefer the SX. The display is almost the same, both are worse than my 28S - I notice there must be some later 48G display that is significantly better than the two displays I have. Anyway, the keyboard of my SX has the high quality I'm used to, while the 48G has a weird tactile response. And the color scheme is of course much more logical on the SX than on the G.

[bill platt]

Hi marais,

Could you tell us where your 48G is made? I suspect it to be Indonesia. Did you buy it new or used? II have noticed that the Singapore made 48g/x/+ are different (better perhaps) from the Indonesian (newer) machines.

regards,

Bill

[marais]

It's a Singapore unit, SG 73600568.

[James M. Prange (Michigan)]

Quote:

---

The only drawback for some people is the color schema of the GX, but
hey, nearly every other HP calc has a better and more ergonomic color
schema than the 49g (blue & red letters on 'metallic' blue...;-)

---

The 48GX adds some input forms and choose boxes, which I often find
more a hindrance than a help, but the old "soft-key" menus are still
available for most things.

Quote:

---

There were so-called multi-memory cards (multiple bankswitched 128K
blocks) for the HP-48SX from TDS (e.g. 256K), I don't know which one
was the largest, I assume that you can use up to two multi-memory
cards in the SX at the same time, so you had a maximum of 512K
independent memory, and the 32K main memory.

---

I have a 1997 EduCALC catalogue (#74) that lists the TDS cards in
256KB and 512KB sizes, and I have one 512kb bankswitched card. It
works in either slot 1 or slot 2, so yes, I assume that you could use
two at once in the 48SX. But note that you can use only one 128KB bank
of the card at a time, and if I recall correctly, switching banks
means doing a warmstart too.

Quote:

---

There were (and still are) also various RAM cards for the GX,
theoretically up to 4MB, but due to an addressing bug in the 48GX ROM
to a max of 2MB.

---

Actually, Klotz
markets a 4MB card. I understand that the addressing bug makes
accessing the last port of a 32 port card impossible, but on the Klotz
4MB card, you can switch which two 128KB banks of the 4MB card will be
used as the last two ports.

Quote:

---

These cards can only be used in port 2 of the GX,
wheras only 32K or 128K cards can be used in port 1 .

---

Also note that with the 48SX, you can merge both slots with system memory,
for a maximum that approaches 288kb, but with the 48GX, only slot 1
can be merged, for a maximum that approaches 256kb.

Quote:

---

Theoretically you can use the TDS multi-memory cards in port 1 of the
GX, but IMHO it doesn't make too much sense, because I doubt you'll
ever need that much memory. Apart from that, you'd have to write your
own driver software for the bank swwitching in ML, because I'm sure
the TDS drivers won't work in the GX.

---

I'm not sure whether I've ever tried the TDS card in a 48GX. Better to
use a 128KB card in slot 1 and the larger cards designed for the 48GX
in slot 2, and save the special bank-switched card for the 48SX.

Regards,
James