The low level RF control for the SLAC LINAC [1] is being upgraded to provide improved performance and maintainability. RF control is through a high performance FPGA based DDS/DDC system built on the SLAC ATCA common platform. The klystron and modulator interlocks are being upgraded, and the interlocks are being moved into a combination of PLC logic and a fast trip system. A new solid state sub-booster amplifier will eliminate the need for the 1960s vintage high RF phase shifters and attenuators.