actually electronika 60 version DOES have ONE preview. It's optional, and, like many early versions, turning it off gives you more points for your pieces then having it on.
How the game was really like back in the day.
0 or 1 preview, controllable by pressing a key
gravity never exceeds 1g.
level advance button (you can advance a level at any time)
nintendo rotation system exactly, but only CCW rotation (CW was added in gameboy tetris, and a prototype of Sega Rotation was added in PC spectrum Holobyte tetris (both S and Z rounded right.)
gravity lock (everything but sega tetris used this for a while)
DAS by keyboard typematic rate. (In practice that means you had to tap unless you messed with it or did a wall charge at low gravity, where it would be pointless anyway)
non locking hard drop (actually it does't always lock, but treat it as locking hard drop for purposes of this challenge)
no soft drop (sega tetris and Atari tetris added that)
no ARE (it sorta exists, but is not very predictable so for purposes of this challenge use no ARE)
little line clear delay.
tetris 3.12 for PC dos, playable under dosbox, with phantom off, is ideal to play this challenge.
