November 11, 2025
When Z meets AoC, the comments speedrun chaos
Advent of Code on the Z-Machine
Retro text-game engine crashes Advent of Code — cue nerd brawl
TLDR: A coder ran Advent of Code on the 1979 Z‑machine, the classic text‑adventure engine. Comments exploded over who did it first (Z‑machine vs. CHIP‑8), whether Infocom really used Lisp macros, and a Sandia lab mix‑up—showing retro tech still sparks fresh curiosity, jokes, and debates.
A retro twist lit up Advent of Code (an annual holiday coding puzzle fest): someone tackled it on the 1979 Z‑machine, the old engine behind classic text adventures. The article walks through skipping raw ZIL (a gnarly, Lisp‑ish scripting language) and using Inform 6 to compile puzzles into Z‑code. But the comments? Pure chaos.
First came the mix‑up comedy: one reader expected the giant physics rig at Sandia—yes, this one—not a text adventure engine. Then the history brawl kicked off. Is Z‑machine really the earliest “fantasy console,” or does CHIP‑8 wear the crown? One camp waved retro receipts; the other argued definitions, proving that nothing divides nerds like the word “earliest.”
Meanwhile, a surgical fact‑check landed: a commenter challenged the claim that Infocom used Lisp macros to write ZIL, demanding evidence and insisting ZIL wasn’t that low‑level. Another chimed in with modern flair, name‑dropping Dialog, a newer language that also compiles to Z‑code—because of course this rabbit hole needs more tunnels.
Practical voices tried to keep it real: Advent of Code puzzles map nicely to text‑adventure rooms, said one, but the second half of a challenge still wrecked them. The vibe? Nostalgia colliding with reality—half museum tour, half bar fight, with punchlines and pedantry in equal measure.
Key Points
- •Infocom created the Z-machine in 1979 to enable portable interactive fiction via compiled bytecode.
- •The Z-machine exists in multiple versions; version 3 was widely supported, while higher versions traded portability for capability.
- •The Z-machine is still used today, though many modern works target the Glulx virtual machine.
- •Developers can target the Z-machine using ZIL (with a modern compiler), but the article cites low-level complexity and limited documentation as drawbacks.
- •Inform 6, developed by reverse-engineering the Z-machine, compiles to Z-machine bytecode and is distributed as standalone C sources for building its compiler.