h@ck3r

What is actually in there

Built, not faked

The BIOS has a SETUP screen, a supervisor password, configurable boot order, and persistent state. Change the boot device and a different operating system starts.

The filesystem models DOS semantics rather than bytes: 8.3 filenames, the read-only/hidden/system/archive attribute set, files that are deleted but recoverable with UNDELETE, and files that are corrupted and throw a bad-sector read error until repaired. It deliberately stops short of true sector emulation, and the code says so — with the reasoning, and the condition that would justify going further.

The BASIC interpreter is 808 lines: tokenizer, expression parser, program store, RUN/LIST/NEW, a period-correct 16-colour palette with graphics commands. The interesting part is the scheduler — it executes a bounded budget of statements per tick and yields, so an infinite loop in a 1992 BASIC program does not freeze a 2026 browser tab. The simulated disk ships real .BAS programs that run in it.

Also present: a second fictional Unix on a hidden drive reached through the BIOS boot order, an encrypted-folder puzzle using real AES-GCM through WebCrypto rather than a pretend cipher, and a 2400-baud modem with a synthesized busy signal and strict dial-string parsing that rejects malformed input. Seven playable in-fiction games, including a text adventure and an ELIZA.

The BIOS, running inside a machine that is also simulated — bezel, floppy slot, power LED. Note the case buttons: PWR / DOS / NVX / RST. NVX is the second operating system, on the hidden drive. The keyboard legend offers (Shift)F2 : Change Color — a real Award BIOS feature, and the kind of detail nobody asks for.

ELIZA, one of the seven playable programs on the simulated disk, running the 1966 DOCTOR script. The pronoun reflection works — you’re saying comes back as I am saying — and mother correctly outranks every other keyword, which is precisely Weizenbaum’s priority scheme. It also fumbles a compound sentence into “How does being ok. your back hurts make you feel?” — and that failure is period-accurate as well, so it stayed in.

The real difficulty

Not any one system — the interlock

Each layer individually is tractable. The hard part is that the puzzle has to thread through all of them — BIOS password to hidden disk to Unix login to encrypted vault to modem to a remote system — with no dead ends and, just as importantly, no accidental shortcuts. A redundant second path through a puzzle is a bug, and finding them means holding the whole dependency graph at once.

A 424-line design document tracks the interlock, and the commit history shows active pruning: entire files deleted specifically so that one clue exists in exactly one place.

One DIR listing corroborates four separate claims at once: UNDELETE.EXE for the recoverable-deletion filesystem, NBASIC.EXE for the interpreter, NCRYPT.EXE for the AES vault, and NVTERM.EXE for the modem. Those four files are four links in the puzzle chain. Also note the DOS button on the case is now lit — it was dark in the BIOS shot, because the machine reports which OS it actually booted.

Honest notes

Where the verification stands

One automated test file. The main quality instrument is an overnight work log whose final column, for each feature, is the method used to verify it — a typecheck, a fuzz run (1,142 random keystrokes, zero crashes), a winnability check, a six-hundred-frame soak. It also records what could not be verified and why, which is the part I would keep.

The game is not finished. It is playable, it is packaged for macOS, Windows, and Linux, and it is a demonstration of construction rather than a completed product.