About

About Ironic Computer Space Simulator Computer Space, Nutting Associates 1971 This is my entry to Retrochallenge 2016/10, a program for the early 1960s DEC PDP-1 computer to run a simulation of "Computer Space", the first coin operated arcade video game of the early 1970s. In 1961 Martin Graetz, Stephen Russell, and Wayne Wiitanen conceived Spacewar!, the first digtal realtime video game, as a showpiece application for the PDP-1. A first, short article on the game appeared in April 1962 and in the following month, May 1962, the game was presented to a stunned public in the course of the annual MIT Sience Open House. Ten years later, in 1971, Nolan Bushnell, presented the very first coin operated arcade video game, Computer Space. Bushnell was heavily influenced by seeing Spacewar! on the PDP-1, but he could not afford a pricey computer for a machine that was to be placed at public locations and to return the investment by quarters. Consequently he teamed up with Ted Dabney (thus Syzygy Engineering) to construct his game in TTL logic (mainly 74xx-series chips) and eventually partnered with Nutting Associates to produce the machines. Notably, Computer Space is not a program, but an electronic device — or, as Nolan Bushnell once put it, a "big, fancy signal generator". 45 years later we attempt — by what may be called an ironic twist in history — to bring the game to the machine which's showcase program had started it all. While Spacewar! stepped out to simulate orbital mechanics and space flight on the PDP-1, here, we're using the venerable machine to simulate the mechanics of another space game. However, we do not attempt an accurate simulation of Computer Space, but rather a game that is similar in look and feel, choosing alternate solutions where a close reproduction would not do for the platform. The program is written in assembler code for the PDP-1 and the resulting object code is loaded into the emulated machine from a virtual paper tape. The PDP-1 Program (v. 1.2, Nov 23, 2016) The program worked out rather nicely and should be fun to play. It models the original arcade game fairly well and even features an explosion effect of its own and some optional enhancements, as well. The major difference to the original Computer Space is the display of a larger, square play field without any clipping. Most amazingly, the game is running at 60 fps (even with some throttle, i.e. idle cycles, to adjust the pace of the game) — a testament to the realtime capabilities of the DEC PDP-1, a computer, which was first presented in 1959. BTW, Please mind that computer space is not an easy game and be ready for some frustration. :-)