Fanuc A20B-2900-0290 ROM 1Mb Memory board. Normally this memory pcb interfaces between Fanuc NC and MC.
Running the 16 / 18 control config in which it stores the system memory, ladder, and programs. The 1024K A20B-2900-0290 ROM memory pcb is available @ DNC today, either as exchange or on an outright basis stock dependent with full testing and repair services are available also. Warranty is 180 days on repair or exchange