ah, the 1620. memories ...
My CS teacher said it was called the 1620 because that is when it was manufactured.
Ours had no disk, just card I/O, but it did have the 128K character core option. The memory cabinet was about the size of a baby elephant, or Rosie O’Donnell on her back.
Wrote my first program on it (”HELLO, WORLD!”) in FORGO during the Camelot era.