Hi jj33,
The FTDI cable (either in the 3.3 V or 5 V version) *should* work just fine on all three platforms, both for programming and serial communication.
On the mac, you should indeed see it show up under /dev, as both /dev/cu.usbserial-xxxxxxxx and /dev/tty.usbserial-xxxxxxxx.
It should also show up in Arduino, in the Tools>Serial Port menu. If it is not there, you may need to install or update the FTDI “VCP” drivers in order for it to show up correctly, and to use it for communicating with the Alpha Clock Five.
Two other things: Consider updating to firmware v2 as soon as possible; it’s much easier to work with. And, please feel free to ask questions here in the forums, hopefully before you get frustrated next time. :)
