It used volatile memory, which was standard for the time, and required a battery backup to keep your data preserved in case the 3 AA cells (which lasted about 700 hours of use) completely drained. No, 700 is not a typo.

The later editions (the Neo and Neo 2) are still compatible with modern technology, since when the Alphasmart is plugged into a computer (or smartphone) via USB, it shows up as a keyboard. Sending your text file to the computer basically just sends all the keystrokes over to your text editor of choice as though you’re typing it really fast.