NASA's Shuttle language survives only as a 1980 scan. I had AI rebuild it.

The complete specification of the language NASA wrote the Space Shuttle's flight software in is a 20-megabyte bag of page images. No text layer. Some pages sit at an angle. That document is IR-542, and nothing supersedes it. If you want to know whether a bit-string partition is legal on the left of an assignment, the answer is a photograph of a page printed in 1980. I wanted HAL/S to run again — lexer, parser, type checker, interpreter — and I wanted AI to write essentially all of it, because the interesting question isn't whether a dead language can be revived. It's what the current generation of models can do when the source of truth has been degraded, and what a human still has to hold. This is the first of four projects that vary exactly that. HAL/S is the easy end: a formal spec exists, real preserved code exists, and an independent implementation exists to check the answers against. Best-case conditions. Worth knowing what best case buys you. The obvious OCR strategy is wrong Run three OCR engines, take the majority vote, move on. This works for prose and fails for grammars, for a reason that took a diagnosis pass to make explicit rather than assume. OCR errors are correlated across engines . Tesseract, Textract and the PDF's embedded Envision layer are all reading the same glyphs at the same resolution with broadly similar priors, so they tend to misread ::= the same way and | the same way. A vote between them doesn't cancel error, it launders it — three engines agreeing confidently on ::: when the page says ::= . And the deeper problem: no aggregation method can recover a candidate that no engine produced. If all three miss a character, fusion has nothing to fuse. For prose that's survivable, because context repairs it. For BNF it's fatal — the metacharacters are the content, and there is no redundancy to recover them from. So the pipeline sorted pages into tiers by how much OCR could be trusted: Tier Content Trust Disposition A Prose High OCR, spot-check B