Tetris followed its original version for Electronica 60 when Vadim Gerasimov, then sixteen years old, ported it to IBM PC. This version spread through Moscow quickly after he and Alexey Pajitnov shared it with their friends.
Download version 3.12 of the first PC version of Tetris from Gerasimov's web page here (Tetris3.zip), and a utility to change the tetromino colors here. Gerasimov mentions at his site that there's an easter egg hidden in the game. It is triggered by pressing Ctrl+A and then Ctrl+D while the game over message is shown (unless in demo mode).
Points are calculated and given only after a piece locks down. No points are given after a piece causes a "game over".
19 minus the number of active rows fallen. Hard dropping causes a piece to become inactive at the point of execution, therefore hard dropped rows are not deducted. If a piece were hard dropped from row 15 to any point below, the drop points rewarded would be 19 - (20 - 15). There is no additional bonus for hard dropping.
3 points * level given for each piece.
Draw next off
5 points per piece. This option can be turned on and off during a game, but it must remain disabled from before a piece spawns until lockdown in order to earn the bonus for that piece.
There are no points given for clearing lines, even for making tetrises. However it's a viable strategy to stack high to earn more drop points if you feel uncomfortable with hard dropping.
None is known.