Teslafan

Hi All :) Is there a tutorial on the TAXI (Transparent Asynchronous Transceiver) Interface? At what voltage levels do the TAXI+ / TAXI- transmit? Can i use TTL or HCMOS to transform the serial bits into parallel Bytes? I have Googled for it and i just can't seem to be able to find relevant information about it, i only find links to obsolete IC circuits. Hence my questions :)