ANSI 1.5B:

  GENERAL
    - Much documentation added
    - Terminfo descriptions
    - Separate `mini' version

  KEYDEFS/KMP (key mapping)
    - Total remake to comply with well-known VT52 `standard', and
      cursor/function/screen keys

  KEYUTIL (keyboard handling)
    - Alpha gives `long' keys instead of RightShift
    - Annuciators don't stay on when other shift key is pressed

  SETKEY (changing key mapping)
    - Long sequence for `+' (key 49) is changeable

  TTY (main program)
    - At program start all shift modes are cleared

  TTY52 (integrated vt52bis program)
    - Completely new

  VT52BIS (vt52bis serial input handler)
    - Completely new
  Changes with respect to VT52:
    - New Esc-sequences for Inverse On/Off, Cls
    - Area-clears leave cursor visible
    - Memory leak repaired