Here's the zip file it gave me of the files it generates along the way: https://static.simonwillison.net/static/2026/turbo-pascal-an...
I had Codex GPT-5.4 xhigh run a check of those files to see if the artifact at the end appeared to use the right data, which isn't 100% fool proof but have me enough confidence to publish since this is a pretty low stakes project!
Anyhow, I downloaded your ZIP file and looked into the disassembly. It seems that the disassembler simply disassembled byte by byte not taking into account that TURBO.COM is both, code and data. Since the x86 instruction set is very tense, pretty much every byte sequence turns into legal instructions. Even the ASCII strings were disassembled. Look at address hex4864 in the file for example - it should be the string "Write block to file" but got disassembled. I wonder how AI managed that obscure file.