Today I received the first XH-W1401 specimen (mine has yellow instead of green 7S-LED displays).

Observations:

• The copper area that serves as a heat sink for the "AMS1117 5.0" linear regulator is too small (yes, it gets hot!)
• The 74HC164 unbuffered shift register that drives the LED columns is clocked by PD1/SWIM (of all pins). Let's see what we can do with this.

I didn't start experimenting with it because I had to fix a bug in the number conversion routine first. I added two features (more address words for peripheral devices, and lowercase numbers for base > 10) while I was at it. The new binary is at the usual location.