The publication of “Practical Wireless” in November 1974 produced a five-part article series showing the reader how to create a version of the popular “pong” game that could be played on a television screen available in a typical British home. [Grant Searle] He wanted to create this project year after year, but it took him until 2008 to find the opportunity to do so. The magazine article printed the PCB layouts on a 1: 1 scale, with a bill of materials and assembly instructions. After each month, the reader will consolidate the project a bit more, with the last month devoted to point-to-point wiring and the final setup. In the coming months there will be some enhancements like scoring system and sound effects, but these are not yet part of the original construction. To understand the build, you need to download a PDF copy of the magazine prints. (And if you’re a fan of electronics like this writer, you’ve already fixed it?)
The electronics are based on pure 7400-series logic, 741 opamp-based ramp generators and, you guessed it, 555 timers. The way different boards have different functions is particularly interesting. For example, in Part 3, PCB described (Board A) is not only a master field / line sync generator, it also generates video signals for the ball, the position and size of which are determined in an analog fashion. Signals from board C (top / bottom base) toggle an isolated flip-flop, changing the direction of the ball when it ‘bounces’ from the edge of the screen. Each board generates its own video signals, which are then combined into a final video mixer (Board E) that simply wires them all together with a composite sync to create the required composite video. It was fed by tapping a UHF video modulator, but [Grant] Choose not to install it for build. The whole thing was wrapped inside an MDF case, wrapped in that dubious mesh-wood-plastic wrap, something some of us fondly remember for that 70s aesthetic.
Pong is a popular classic game that we’ve covered in many, many forms over the years. Here is one that is completely mechanical, another that uses the original PCB with a visually striking twist and finally, a complete virtual simulation of the original arcade circuit courtesy of Falstad. We are sure that much more will come.
Thanks [JohnU] For the tip!