Tetris (PDP-11, 1984)

Lore & Background

In the summer of 1984, Alexey Pajitnov, a research programmer at the Dorodnitsyn Computing Centre, was looking for a way to fill idle time on the Electronika 60 workstation he used. He drew on the puzzle of pentominoes and the idea of a falling-block game, and wrote the first version of Tetris in C. The choice of C was not incidental: it meant the source could be recompiled on any Unix system, and the PDP-11—DEC's long-lived 16-bit minicomputer, still ubiquitous in Soviet and Eastern European research labs as well as Western universities—was one of the natural targets. A colleague or lab-mate compiling the same source on a PDP-11 running Unix would get a functionally identical game, rendered to a character-cell terminal rather than a graphical screen.

In Their Own Story

The terminal hums in the corner of the lab, its green phosphor glow the only light after the others have gone home. You type a command, hit enter, and the cursor blinks twice before the first tetromino drops—a long I-piece, slow as a thought forming. Your fingers find the arrow keys by memory. You nudge it left, rotate, drop. It slots into the gap you left three lines up. A line clears, the grid shudders, and the next piece is already falling. There is no music, no crowd, no score that matters. Just the rhythm of shape and space, the quiet clack of a PDP-11's cooling fan, and the particular satisfaction of a clean stack at 2 a.m. in a room that smells of cold coffee and warm circuitry. You clear another line. The game does not congratulate you. You do not need it to.

Reader's Guide

Platform: DEC PDP-11 minicomputer, running a Unix variant (likely Unix V6 or V7). Year: 1984. Developer: Alexey Pajitnov, working at the Dorodnitsyn Computing Centre. There was no commercial publisher; the code was a single C source file compiled locally.

Mechanically, this build is the purest expression of Tetris. The player controls a single falling tetromino using cursor keys on a terminal, rotating and shifting it before it locks into place. Filled rows are cleared. There is no hold piece, no next-piece preview, no guided rotation, no line-clear animation, and no sound. The display is a character-cell grid on a monochrome terminal—likely a VT100 or similar—rendering blocks as filled or half-block characters. The game loop is simple and fast, limited by the terminal's refresh and the PDP-11's processor speed.

Aesthetically, it is austere: a black screen, green or amber text, a rectangular grid, and a score counter. There is no sprite art, no background, no color. The visual identity is entirely typographic.

Culturally, this version existed in the closed world of Soviet academic computing in 1984. It was not licensed, not distributed commercially, and not visible to the outside world. Its significance is historical: it is one of the earliest forms of the game that would become a global phenomenon. There is no licensing controversy attached to this specific build, as it predates the complex rights disputes that would later surround Tetris. The notable omission is everything: no music, no graphics beyond text, no multiplayer, no persistent high scores.

Did You Know?

• The original Tetris was written in C, which meant the same source code could be compiled and run on any Unix system, including PDP-11 minicomputers common in 1980s research labs.
• The PDP-11 version had no sound, no next-piece preview, no hold piece, and no graphical sprites—just a character-cell grid on a monochrome terminal.
• The PDP-11 was a 16-bit minicomputer from Digital Equipment Corporation that remained in wide use in academic and research institutions well into the late 1980s, even as DEC transitioned to the 32-bit VAX line.
• Tetris was created as a personal project by Alexey Pajitnov and was not intended for commercial release; its spread to the West happened through informal copying and sharing of the source code.