How do you know which version you have?

I have two original Tamas, but I dont know which type of version they are to find out more about them...al the box said was #1800...I think I remember someone saying gen1 or gen 2..but I dont remember...One is white with black buttons and blck around the screen, and the other is clear blue with yellow buttons.

There are a couple of differences between the Gen1 and Gen2 Tamas (before the IR connection versions).

The background pattern behind the tamas screens is different:

Gen 1: checked / squares pattern

Gen 2: wavy pattern

The games your tama plays is different:

Gen 1: guess which way the tama is going to look

Gen 2: high / low game

There's lots of useful info about older versions of tamagotchis on https://www.tamenagerie.com (Mothra's web site) and on other sites like https://www.mimitchi.com (Tamagotchi Planet)

Here are pictures where you can clearly see the backgrounds.

P1: https://i59.photobucket.com/albums/g310/bin...1background.jpg

P2: https://i59.photobucket.com/albums/g310/bin...2background.jpg

It's probobly version 1.