Needing help powering up a Sanyo ICC-801D

[sislasl]

Hi,

I have found a Sanyo ICC-801D calculator without an AC adaptor. I want to test the calculator's functionality and therefore need to power up the calculator. The AC Adaptors which work would be a Sanyo CU-82 or Dictaphone CU-1680 but I found no place where to get one.
I have read that you can also power it up by connecting 6.6 VDC.
Now I would like to know how to do this.
Since I have never done something like this before I assume I have to open the calculator's case and connect the cable of some generic AC Adaptor with variable VDC to some spot inside the case. Can anybody tell me how to do this exactly and what kind of AC adaptor I need?
Thanks in advance