|Rotation system||Sega Rotation (no wallkicks)|
Sega's 1988 Arcade version of Tetris was the version that took Japanese arcades by storm, becoming one of the most commonly known versions of the game. Due to its popularity, it became the base of rules for many other Japanese games created later on, both licensed and unlicensed. Such games include the TGM series, Tetris Plus series, Shimizu Tetris and, to less extent, DTET. It was one of the first games to instate lock delay, improving maneuverability greatly at high speeds compared to games which did not have the feature.
Being an early game, there was only one rotation button, which rotated counterclockwise. The game also contained no wallkicks and no hard drop. However, many of the elements that exist in later games can already be seen here, such as 1G DAS movement, lock delay, ARE, and rotation/movement processed before gravity - allowing for synchro moves to be performed at 1G fall speed. One rule element not commonly seen in recent games is the existence of the field ceiling. The field height is fixed at 20 cells, and any rotation that would exceed that height would fail.
It was one of the first games released in Japan to popularize the "marathon" play model of playing endlessly against increasing speed for survival, as opposed to beating levels or clearing a predefined number of lines.
- Speed levels, in frames per row
Current piece speed is located at C7000Ah in the RAM.
- Level advancement requirements
There are 2 ways to increase a level.
- Erase 4 lines.
- Put any tetromino after the "level timer" reaches to certain value. (Level will not increase if line clear happen.)
The "level timer" will increase every 256 frames. If the level increases, the timer will be reset in 0.
Current level timer is stored at C72336h in the RAM.
One characteristic of this version of Tetris was the existence of a "Power-on pattern". This referred to the game's behavior that the string of pieces it dealt in the very first game after starting up the system was always the same. This was most probably caused by the state of the randomization seed in the system. After its discovery, players began constructing gameplay plans around the power-on pattern in order to max out the score in the least lines possible. Sega's 1999 version of Tetris (Arcade, Dreamcast) pays tribute to the power-on pattern, by dealing the sequence in the final level of the single-player game.
For MAME players, unless you are playing the bootleg, you must delete your nvram before playing to get the poweron pattern. The B-system version has a different poweron pattern, and does not require you to delete your nvram.
Flash Point also contain a poweron pattern, not saved in nvram, and uses it for every level you play for the entire game.
Bloxeed contains a poweron pattern as well but you must delete your nvram. Additionally if you "continue" you will recieve the pieces in the same order again! However, the powerups are NOT included in the poweron pattern, and are truly randomised.