Tetris (Sega)

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.

Gameplay specifics
Being an early game, there was only one rotation button, which rotated the Tetromino counterclockwise. 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. The game did not have hold and hard drop.

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 ala Atari's own Tetris for arcades.

Techniques
See Tetris (Sega) Techniques

Details

 * Soft drop: 1G
 * Lock delay: 30 frames
 * ARE: 30 frames
 * Line clear delay: 42 frames
 * DAS: 20 frames

Current piece speed is located at C7000Ah in the RAM.
 * Speed levels, in frames per row

There are 2 ways to increase a level. 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.
 * Level advancement requirements
 * 1) Erase 4 lines.
 * 2) Put any tetromino after the "level timer" reaches to certain value. (Level will not increase if line clear happen.)

Power-on Pattern
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. It even restores the pattern upon reset, which not even the bootleg will do.

Flash Point also contain a poweron pattern, and uses it for every level you play for the entire game, and if you continue. If you fail to continue, the next game continues where the failed level ended in the poweron pattern. Again, unless you are playing a bootleg without nvram, you must clear the nvram to get the poweron pattern back.

Bloxeed contains a poweron pattern as well. 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.

Availability
A fairly accurate representation of the game, along with Tetris: New Century, Flash Point and Bloxeed are availabile in the Japanese PS2 game Sega Ages 2500 Series Vol.28 Tetris Collection.
 * Games