 It used the KA691 CPU module containing an 83 MHz (12 ns cycle time) NVAX microprocessor with 512 KB of external tertiary cache.The VAX 4000 Model 700A, code-named ""Legacy"", was introduced on 12 October 1993.It used the KA692 CPU module containing a 100 MHz (10 ns cycle time) NVAX microprocessor with 2 MB of external tertiary cache.