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Cake day: June 23rd, 2024

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  • Trojan is any malware that pretends to be a legit program. It does not need to have backdoor or info stealing capability even though most malware (trojan or not) today does. For example, pre-Internet trojans might just invisibly install themselves along the actual program they were bundled with and then nuke the system on a certain date. Antivirus companies would even advance the date on their systems in hopes of detecting these and being the first to develop a patch.

    But since this program is not malicious, it just straight up hogs system resources and/or crashes it due to a mistake, it cannot be considered malware and therefore not a trojan.

    Certain Intel processors from around 2000 would crash everything when loading the 4 bytes F0 0F C7 C8 into a specific register. Would you consider this a backdoor because it allows any program to crash the system? I wouldn’t say so, crashing Windows 98 was probably not too hard anyway…











  • Popular myth but untrue.

    The ROM is exactly 40 kiB or 40 960 bytes. The NES outputs video at a resolution of 256×240=61 440 pixels. The game never switches palettes mid-frame and thus the highest possible number of colors (of the 64 available ones, of which 55 are distinct) in any screenshot is: 4 sprite palettes × 3 non-transparent colors per palette = 12 colors among all sprites; plus 4 background palettes × 3 selectable colors per palette + 1 selectable color shared between all palettes = 13 colors in the background; or 25 colors in total.

    Even one of the most basic lossless image formats, GIF, can use an n-bit palette of 2−1 arbitrary colors plus transparent, where 1≤n≤8. For n=5, we can store up to 31 colors at 5 bits per pixel, or 307 200 bits total, which is 38 400 bytes. The palette entries, size etc. will take about 200 bytes at most, and LZW compression built into the format (or even better, whatever PNG uses) can be used to reduce the file size further (significanly because there are huge areas filled with solid color or patterns).

    I’d bet it’s possible to make an NES ROM that does nothing but fill the screen with noise-like tiles and switches the colors mid-frame, likely in just 8 kiB of video ROM plus 2 kiB of program ROM, whose screenshots will never compress to below 10 kiB in PNG format, though.