A few weeks ago, Matthew Krotzer asked for Sigma+ to work in StopWatch mode. This is now the case.
Time in decimal format is added to the X summation registers and the counter is added to the Y summation registers.
So in StopWatch mode, if you press A, i.e. Sigma+ several times, you will add the current time and reset it to 0. Once you exit, press f-5 to see the averaged round time and f-STO to see it in H.MS mode.
Pressing + will store in memory & add to summation registers. It is the equivalent of pressing both Enter & A/Sigma+ at the same time.
Another change: when in round time, i.e after pressing A, . or +, the total time is also displayed instead of the STOPWATCH label.
I guess Marcus will build and upload the new firmwares & emulators as soon as he can (but it may take a few days at least). In the meantime, these new functions are in SVN.