the hp48g was the top of the range hp calculator until the hp49 was introduced. the hp49 is much the same as the hp48gx shown here, but with more memory and an improved symbolic engine, the latter which can be downloaded and installed into the hp48g makes it operate pretty much as a hp49.

the 48g superseded the 48sx, originally 1990, and was the last model built using the toggle-click style keys, which i have always found to be well built and reliable. the 49 is more cheaply constructed and has rubber keys.

there is lots of stuff out there for this machine (and its compatibles) on www.hpcalc.org

my main gripe against this machine is that i have to get out the manual every time i want to do anything and quite often i accidentally put the machine into some weird mode from which i cant escape.

i also think its too slow. way too slow. apparently the 49 is much faster. thats good. this is the 48gx which has more memory built in than the original 48g and can still be expanded further. this is definitely good, because i needed to load quite a bit of software into the machine to bring its symbolic and ui features up to scratch and then i need space for my own stuff.

on the plus side, this machine is very well constructed indeed. its a pity that the performance and capacity of the 49 was not made into this form factor.