anchor.diff:              case 1060:
               case 1061:
               case 2004:
  -              // TODO(vtl): FIXME soon.
  -assert(false);
  -              break;
  -default:
  -// TODO(vtl): FIXME soon.
  -assert(false);
  -break;
  +              assert(!assertFailOnUnimplemented);
  +              break;
  +            default:
  +              assert(!assertFailOnUnknown);
  +              break;
             }
           }
           break;
  
positive.code:         break;
        case 98:  // 'b': Repeat the preceding graphic character.
          // TODO(vtl): FIXME soon.
  assert(false);
          break;
        case 99:  // 'c': Send device attributes.
          // TODO(vtl): FIXME soon.
  assert(false);
          break;
        case 100:  // 'd': Line position absolute.
          if (_csiC1 != 0) {  // Only accept no C1.
  
negative.code:             case 3:
              case 4:
                // TODO(vtl): FIXME soon.
                assert(!assertFailOnUnimplemented);
                break;
              case 5:  // Reverse video.
                reverseVideo = true;
                break;
              case 6:
                // TODO(vtl): FIXME soon.
                assert(!assertFailOnUnimplemented);
                break;
              case 7:  // Wraparound mode.
                autoWrap = true;
                break;
              case 8:
              case 9:
              case 10:
              case 12:
                // TODO(vtl): FIXME soon.
                assert(!assertFailOnUnimplemented);
                break;
              case 18:  // Print form feed.
                break;
  