` COMPUTE! ISSUE 156 / SEPTEMBER 1993 / PAGE 94`

 PentaCalc. (Headgate desktop calculator for Windows) (Software Review) (Evaluation) by Charles Idol It's really a pain to be sitting before that big, powerful computer and have to resort to your hand-held calculator for a result to be entered into the document you're working on. Windows does a nice job of meeting this need with its built-in calculator. PentaCalc, which runs under Windows, extends this basic capability with many additional features. The program offers five modes of calculation. The basic mode is the scientific calculator, which performs all the usual arithmetic operations plus trigonometric, logarithmic, and exponential, including e^x. You can choose from binary, octal, decimal, or hexadecimal number bases for these calculations. In addition, there's a time base that lets you calculate the time difference between two dates and will tell you the day of the week of any date over a very wide time range. Another mode is that of a ten-key tape calculator. Although limited to simple arithmetic operations, a "tape" record is kept of the entries and operations, and you may go back over the tape to correct errors or change entries. Text labels of the entries are allowed, and you may save or print the tape. A tax key is offered that shows the tax on the current total at a tax rate you define, just like at the grocery store. The financial mode performs time-value-of-money or cash-flow calculations. It offers convenient definition and evaluation of investment goals, and it will create an amortization table for you on your mortgage. It's a very powerful tool if you pay attention to what your money is doing - and should be doing. The unit conversions mode is comprehensive; it converts just about anything into other units. Length, area, velocity, volume, pressure - there are 28 dimensions in all. The volume units are interesting, offering conversions between the usual quarts, gallons, and liters, along with cups, tablespoons, and teaspoons. If you need to scale a recipe for eight down to two, you might find this useful. Finally, the statistics mode operates on a list of numbers, calculating the mean, median, standard deviation, sum, or range, as you prefer. You may edit the list to make changes, additions, or deletions. In all modes, numbers can be transferred to or from other Windows documents by way of the Clipboard. PentaCalc is an unusual calculator, offering many features not commonly found. Fast and convenient, Pentacalc could be a most useful a your Windows utility library.