1   Description

This is the first advanced calculator I have bought for myself. I have previously had an Commodore C128 together with my brother and sister. I bought it to use it in school.

I gave it the name marble because it is the most robust electronic device I have ever seen. I actually (by accident) let it fall over 7 meters down on a marble floor. The result was that it opened up some (and it did not work), but it was just to push it together, power it on and use it. :)

2   Gallery

3   Specification

Manufacturer	Texas Instruments
Model	TI-81

4   Functionality

• Matrix manipulation
• Graph plotting
• Simple programming
• More or less advanced calculation

5   Status

Almost always off (it goes of after a couple of minutes of inactivity). This means that the batteries lasts for a very long time. I have not changed them for over four years. When I used it almost every day I had to switch them every three month or so.