Processor board in base of drawer
U403 is:
  Motorola
  MCM7681DC
  8206
U706/ROM0U is:
  TMS
  2532JL-45
  DBP8140
  label:
    CC
    0.6H
U711/ROM0L is:
  Hitachi
  HN462532G
  label:
    CC
    0.6L