Which BASIC pocket computers make the best calculators?

[Dave Britten]

I've been slightly expanding my collection of pocket computers lately, and I've noticed that while most of them are very solid computers, and generally have modes that allow them to be used as calculators, none of them really seem to hit the same ease of use of a programmable calculator for working out problems.

The Casio computers, which are some of my favorites, provide a smart choice of features that make them well suited to portable use, and they have math capabilities on par with most of their early graphing calculators (minus the graphing). Even the simplest, cheapest models generally provide 10 separate program areas to allow for storage of multiple programs without line number conflicts, and programs are allowed to call one another much as in Casio's early graphing calculators.

But the biggest misstep with all the Casios I've used which I feel makes them rather poor calculators is that they have no replay feature. Once you type an expression and press ENTER, that expression is gone, even if you get an error! If you want to correct errors or modify the calculation slightly, you have to retype the whole thing. Some models have a function memory and you can press the IN and OUT keys prior to ENTER so that you can recall the expression afterward, but this is clumsy and unintuitive. For me, this limits the otherwise excellent fx-730P to being useful only for writing/running programs.

The Sharp computers seem to handle calculator use more elegantly, with a replay function that lets you revise your previous entry. And I particularly like the combination of the DEF mode/key and AREAD function to start a labeled program directly from the keyboard and take the current value in the display as input (the Wizard BASIC card lacks this feature for some reason). This allows for very calculator-like usage, as far back as the original PC-1211. The EL-5500 models include a separate CALC mode that behaves a lot like Sharp's algebraic calculators of the time, probably like an early EL-506, however there's no way to run programs in this mode. But it does make for a very nice scientific calculator. The Sharp Wizard BASIC card also offers 20-digit double precision math and variables.

I feel that the Sharp computers suffer a bit on the computer side of things when compared to Casio, as they only provide a single program space (the MERGE command can load multiple programs from cassette, but you can only view/edit the last one loaded, and all the hidden programs have to be called by label). Also, on the models I've used, the PRINT command doesn't let you end the argument list with a semicolon, and INPUT will only accept a single string literal as a prompt, preventing you from including values of variables in your prompts. The Wizard is a bit more flexible here.

And of course there's the HP 71B, which can hardly be called a "pocket" computer. It does a pretty decent job as a calculator, though, and it's got probably the most complete implementation of BASIC seen on a handheld. If you're not running in CALC mode, then you run the risk of your expression being misinterpreted as a line of BASIC code, and it doesn't have anything quite as simple and elegant as Sharp's DEF/AREAD combo, though I suppose one could use a combination of user keys and DISPLAY$/VAL to similar effect. It's got that rather polarizing CALC mode, though like my Sharp EL-5500, you can't run programs in this mode either (user-defied functions are still available).

All of the Casio, Sharp, and HP models I've tried have reasonably good debugging/tracing features, though the HP 71B really shines with the inclusion of SST and TRACE VARS.

Are there any pocket computers that have successfully overcome all of these limitations simultaneously? Honestly, a Casio fx-7700GB with GOSUB, some kind of trace mode, an IF/THEN statement that behaves like BASIC and skips everything else after it on that line, and maybe Sharp's AREAD command would come pretty close.