ADM3a was a terminal, not a computer. I used to use these two in around 1976 or so. And the hjkl pattern has nothing to do with this or any other terminal. The ASCII control codes for Ctrl-H, Ctrl-J, Ctrl-K and Ctrl-L were used to make the Teletype's printing carriage move left, down, up or right. Bill Joy's innovation was "modes" so that Ctrl-H did not delete the character when it moved left, etc...