+## Raspberry Pi Pico note
+
+Early firmware has [this issue](https://github.com/micropython/micropython/issues/6866)
+affecting USB communication with some PC's. It particularly affects code which
+issues `print()` only occasionally: the application appears to have failed. The
+missing messages appear when you press a key. Hopefully this will be fixed soon
+(note dated 8th March 2021).
+