- HP-35 ( one in box with manuals).

    - HP-45.
    - HP-55.
    - HP-65.
    - HP-67.
    - HP-80.

    - HP-91.
    - HP-97. ( one in carton box with manuals).

    - HP-21.
    - HP-22. ( In box with manuals)
    - HP-25.
    - HP-25C.
    - HP-29C.

    - HP-33E.
    - HP-33C.
    - HP-38E.


      - HP-9100B.


    - HP-9823.

    - HP-46.

    - HP-41CV + Thermal printer + HP-IL. ( + DM-41L )

    - HP-11C.
    - HP-12C.
    - HP-15C.
    - HP-16C ( Computer math calculator like TI-Programmer or Casio CM-100 ). ( + HP-16CC)

    - HP-28C.
    - HP-28S.
    - HP-48SX + 2 * 128K ram card.
    - HP-32S.
    - HP-42S.

    - HP-35S.

    - NP-25. ( HP Woodstock / Spice microcode emulation)

Calculation of x! : x!