I'm afraid I don't know why the MICROBIT drive wouldn't be mounted. You'd be better off asking on the micro:bit forums - they may have some ideas?
As far as I know, the USB connection is the only way they suggest that you update the firmware.
OK, thanks anyway ... if I solve, I'll write you how I did!
:-)
@Gordon started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I'm afraid I don't know why the MICROBIT drive wouldn't be mounted. You'd be better off asking on the micro:bit forums - they may have some ideas?
As far as I know, the USB connection is the only way they suggest that you update the firmware.