3.7. Give Me Feedback

James: When I first started writing PCalc, I wasn't yet very accurate with the iPhone touchscreen keyboard and the visual feedback of popping up each key as you type was a great help. It seemed obvious that you would want some similar system for entering numbers into a calculator, so I spent quite a while studying and emulating the Apple keyboard so that PCalc would give similar feedback when you tap a button.

On the desktop version, if the calculator wants to tell you you've done something wrong it beeps at you. If you have the volume turned all the way down, it flashes the whole screen. The first-generation iPod Touch, which was what I was developing on, didn't even have a speaker or vibration, so I couldn't use those. And it's a bit obnoxious to have something beeping at you on a portable device, as you are more likely to be out in a social situation. So I tried to cover all the bases, making the LCD screen flash as well as vibrate, if possible.