I saw this interesting visualization of Atari 2600 binaries. It makes me want to do something similar, but arrange the instructions according to the position of the raster beam when the instruction is executed rather than the position in the ROM. The 2600 is a unique platform in that it lacks a frame buffer, so to produce coherent images, the code must be synchronized with the raster beam. If we make an image that has 4 horizontal pixels per color carrier cycle, that gives an 912 pixel wide image. There are 76 CPU clock cycles per raster line and instructions take 2-7 cycles giving us 24-84 horizontal pixels per instruction, which (with a bit of squishing) ought to be enough. A raster line would have to correspond to a line of text so we probably wouldn't want to show a full frame (field). However, a typical game will only have a few different "line sequences" so a full frame image would be very repetitive anyway.
Ha. This is great, Andrew. Warren Robinett was my housemate while I worked at Xerox PARC. He used to bring this Adventure game home for us to play in the living room, while he was developing it. He did not tell a soul about the secret dot in the game, that, if you took it to the correct room, in the correct order, made the screen go, "Created by Warren Robinett." He also did not mention the name in the screenshot you show. Not, that is, until the day Atari received their first letter from a fan who had discovered it.
It took discipline not to reveal it. Ethics to put in the hack in the first place. And dedication to make the first graphical adventure game. Warren used to sit at the kitchen table and we would all have long philosophical conversations about creators and credits and royalties.
So lovely to see it actually displayed, so poetically, here. Thank you for sharing this.
That's fantastic! I read an article about Adventure a while ago and it seems that it was quite an incredible piece of engineering, even by the standards of the 2600 where to even get an image on the screen requires tricks that are today considered deep, black magic.