I noticed a difference between the behavior of the QT emulator and the real calculator that you might be interested in.
If you have the (Edit Preferences Display Use Real Fonts) enabled, and you enter the following sequence:
[yellow][SF][D][5][+/-][Enter][0][/]
The emulator display will show "Infinity", but the real
calculator will show "-Infinity"
Anything that would generate a "- Infinity Error"
shows "Infinity", but should show "-Infinity" (When flag D is set)
Also if the (Edit Preferences Display Use Real Fonts) is disabled
the emulator shows"-Infinity" just as the real calculator does.
These tests were performed on version 3436 of the QT emulator.
Edited: 24 July 2013, 1:18 p.m.