Hewlett Packard HEW48GII Graphic Calculator

One of the best things about this calculator is how works with objects, so that the form a complex number is irrelevant. In some calculators complex number operations work only on rectangular forms. With the HP48gII (as well as the HP-49g+ and HP-50g) you select the display format but can enter the values in either rectangular or polar form which is a HUGE timesaver for electronic circuit calculations. This is true not just for command line entries, but also for the matrix writer feature so that using mesh current and similar simultaneous solution techniques is extremely simple.

Another great feature is that the calculator stack displays matrices and vectors in matrix and vector form, rather than the older, clunky nested bracket form that the HP-48gx used. Rather than showing [[1 2][3 4]] the calculator will display a 2 x 2 matrix. The same is true for other expressions, such as integral, differential, and summation displays.

The calculator also has some (at least for me) "stupid pet trick" features that are kind of fun. The "Exact" mode, for example, will allow you to preserve full accuracy up to so you can see all the digits for factorials, integer summations, and large primes. The calculator range is just within 1E-500 and 1E+500 so it will handle just about any numerical calculation.

There are some bad features. The HP-48gII I have will NOT work with most AAA batteries: it seems that the battery contacts work only with certain brands, such as the Maxell Free and Ray-O-Vac alkaline batteries. The Maxell lasts a while, but the current draw on the Ray-O-Vac causes the calculator issues a low battery warning after only a few months even when a battery tester indicates that the batteries are still good. The HP-49g+ and HP-50g do not appear to suffer from this problem.

Another word of warning: be sure to use your calculator at least a couple minutes once per month. If you will not be using it, remove at least the AAA batteries as they can be driven into reverse charge and leak.

Another bad feature is that the full manual is available only as a PDF file and it is extremely hard to find some information on using the calculator. The printed user's manual that accompanies the calculator is useful for learning how to use common features, but says nothing about how to used the more advanced functions like the fast Fourier transform (FFT).

I actually rate the calculator 4.5 overall. For the money I think it's an excellent product to own and a good successor to the HP-48gx, light years ahead of HP's previous attempts.