NESOS gives the 8-bit system a graphical desktop, 8 small files, and it’s amazing

When you played the Nintendo Entertainment System, you were close to the hardware. That’s why you can achieve remarkable hacks, like playing Tennis hot start faulty Super Mario Bros. worlds. The chips, the memory, the card – everything has been designed to maintain the small card inside your cartridge (that and to prevent unauthorized games). There wasn’t much room for anything else in the early to mid-1980s.

Enough room, though, for a bespoke 2022-built OS, if not barely. Inkbox Software’s NESOS 1.0, a 48K operating system, has “two main applications, word processing and settings,” according to Inkbox. The settings app gives you seven sliders, 53 background colors, and the ability to delete all eight files that can fit in up to 2K of NVRAM (i.e. built-in memory that doesn’t leak data when the system loses power). That’s 832 bytes each, or about a full screen’s worth of memory. However, you can drag these eight files anywhere on the desktop.

NESOS (pronounced “nee-sohs”, according to its creator) is entirely graphic. Inbox notes that there is already a command line system, Family Basic, for the NES and its Japanese ancestor, the Family Computer/Famicom. “I want NESOS to look like a real operating system that Nintendo might have created for the NES at the time. What would that have looked like? says the creator in his video preview.

Inkbox is no stranger to NES programming, or original code projects that come across as wonderful art. They previously built a fruit-based MMO in less than 40 hours (apparently more active), a Super Mario ROM Hack that redesigned the game in the style of Ming Dynasty Tale Travel westand a Chinese word processor for the Apple II, implemented natively on the Apple II.

The NES gave Inkbox two 256-slot sprite memory grids, one for the foreground and one for the background, although the system could only display 64 sprites at a time. You can, however, combine the 8×8 sprites into larger shapes for the OS and UI. As for typing, a keyboard was included with some versions of Family Basic, the HVC-007. Inkbox imported the characters used in Super Mario Bros., gave the keyboard additional shortcuts, and it had a little typing app going. If you’re using a standard NES controller, you hold A to cycle through characters, press B as a spacebar, and hold Select with either of these keys to invert them.

Inkbox’s video goes on to explain how it all works in NES memory, involving manipulation of the Picture Processing Unit (PPU), giving its NES virtual cartridge the same type of storage as battery-powered games, and shuttling each file, byte by byte, between them.

You can download a ROM compatible with the NESOS emulator on the Inkbox site or on ROMHacking. Two-frame, eight-pixel hats off to Hackaday for pointing us to this marvel.