Bit number 3 (the fourth bit) is unhappy

Thanks to Ariel Cotton for bringing a typical bit failure to my attention.

Why is this happening?

Easy! One of the bit in each of the affected characters is flipped. In particular, the 4th bit, the number 3 bit as we start counting at zero.

The dollar sign ($) is really a comma (,), and the 'F' is really an 'N', the 'g' is really an 'o', and so on.

How's that?

Well, here are the bits side by side: (thanks to Open two Calculators at once )