Even back in the Lisp Machine days, array processors were used for neural network stuff. You could get an LMI or Symbolics with a floating point accelerator (a

Even back in the Lisp Machine days, array processors were used for neural network stuff. You could get an LMI or Symbolics with a floating point accelerator (a Weitek chip), or with an array processor board and library (a whole bunch of Weitek chips and memory, for MIMD or SIMD operation).