About iSpacewar!

Background info on Andrew's art project of creating a "1:30,000 scale working replica" of the world's first video game (1962's "Spacewar!"). running on a simulation of one of the first commercially produced computers (DEC's PDP-1), and subsequent creation of a smartphone version.

Click photo above to play the finished full screen version optimized for smartphones.

Maneuver with retros and thruster; avoid the star's gravity; Left+Right risks Hyperspace; fuel and torpedos have limits.
Touch pads on screen or use keyboard: Left/Thrust/Right/Torpedo = "Wedge" ship: ASDW | 7412, "Needle" ship: JKLO | 3698.

Digital Equipment Corp's PDP-1 was the size of several refrigerators and cost more than $120,000 (when earlier machines cost millions). It was among the world's first transistorized computers, supplanting the fragile slower vacuum tube machines of the 1940-50s. It was designed with the assistance of MIT and 53 were made in 1959-1962. It had 4K words of magnetic core memory and could perform ~200,000 additions per second. The PDP-1 was especially noteworthy for including a vector CRT, pioneering the technology of computer graphics.

This replica is running the actual 1962 code (exactly as it would have been punched on paper tape) laboriously recompiled from vintage assembler source by computer historians, interpreted by a Javascript emulator implementing the PDP-1's instruction opcodes set. For perfection, I even painstaking coded a lean simulation of the CRT's phosphor persistence (frame point sets periodically captured to circular aging buffer then re-rendering from oldest with fading) creating the faint green ship shadows. I've shared the source on GitHub. More backstory on related subjects offsite. Made possible by the brilliant work of and

I initially created it with the intention of building a tiny working model, but realized it could also work as a smartphone webapp. Though a few apps bearing similar names exist, I believe this is the first touch capable version running the vintage game code. On iPhones/iPads, open in Safari then use "Add to Home Screen" for later full screen use. Instructions and touch areas are shown until users begin play. Try it now by clicking the photo below:

Below is the finished 4"x6"x0.3" artwork which started this project, running a tiny embedded version:

The screen dimensions in the artwork are actually just 1/10th scale (the original had a 9"x9" active area versus the replica's 1" diagonal screen), but overall volumetric comparison picks up several orders of magnitude due to the replica being relatively two dimensional. Cited ~1:30,000 scale compares volume based on replica size of 4"x6"x0.3" versus combined volume of basic PDP-1 components including the 6'x3'x7' main chassis and the 2'x2'x4' model 30 screen and logic and the 2'x2'x2' keyboard and drivers. Scale is arguably much higher but for simplicity this comparison ignores the PDP-1's large separate specialized power conditioners, HVAC and office space, as well as the replica having ten times the clock speed and a million times the memory. The photo used is a heavily composited amalgam of the main PDP-1 parts rearranged for visual clarity. See actual vintage photos here.