Processor board in base of drawer
  sticker 8010-11818-01 (Corvus p/n)
  rev A
U309/MAPPER is:
  Signetics 
  N82S181N K8413
  label is:
    CC0.5A
U706/ROM0L is:
  Hitachi
  HN482732AG-30
  label:
    CCB
    17L
U710/ROM0U is:
  Hitachi
  HN482732AG-30
  label:
    CC
    B17H