STUDI/O
At the time I realized there was no inexpensive way to get audio from an ADAT machine to and from a computer, so I started working on it.
Because the only ADAT interface chip at the time was a complete nightmare, I ended up designing my own with an Altera FPGA and a TI PLL. Actually inside the FPGA were several digital PLL's, but I used the TI PLL for some extra filtering on the master clock.
Since it was an FPGA, I could also use it to do other formats - so I could switch the optical connectors to do SPDIF as well.
The boards could also read ADAT Sync (a sample accurate timecode from the ADAT machines) and syncronize up to 4 boards together.
The 'sync' board with the ADAT sync connector also had a couple of BNC's - which were connected to the FPGA. So instead of just word clock, with different FPGA programs I made them AES-3 (AES/EBU over BNC), and LTC (timecode) I/O's.
One of the cool things about the board is that all the firmware - the DSP code for the 56301 and the FPGA code were all contained in the driver. So we literally upgraded the hardware in the field - adding features for several years, which helped the board stay in the game for a while.