# Base Station – Support

Listed below are issues, questions, and suggestions identified via e-mails to us or reviews on the App Store, along with our best attempts to answer or address them. Thanks to everyone who provided reviews (and especially thanks to those that provided constructive feedback and helpful suggestions)!

Got your own issues, questions, or suggestions? Please write us at any time!

### 1. I noticed that on the base conversion page, if you put AB.C in the hex field the app incorrectly converts the number in the base 10 field to an incorrect negative number. -84.25.

If expecting a positive number, like 171.75, tap the gear on the right side of the navigation bar in Base Station to change all numbers to unsigned (positive) or to turn off 8-bit signs.

If expecting a different negative number, such as -84.75, remember that negative binary numbers are created with two's complement arithmetic. Essentially, to convert AB.C to a binary fraction, start by splitting the integer from the fractional part: AB + .C. Focus then on AB. Converting to binary, you get 1010 1011. Since the high-order bit is set (and assuming you want to allow 8-bit negative numbers), this is negative. So we need to use two's complement arithmetic to find the negative value in decimal. First, invert using one's complement and you get: 0101 0100. Now add 1 so you have a two's complement inversion and you get: 0101 0101. Then in decimal, this is -85. The trick to the fractional part is NOT to invert. .C is .11 (or .1100) in binary, and therefore, .75 (.5 + .25) in decimal. Finally, add the two parts in decimal: -85 + .75 = -84.25!