Retro Networks#

Gianpaolo Del Matto - THE PHINTAGE COLLECTOR

• Why: Looks like a nostalgia talk and is, for two-thirds of it (10BASE5 vampire taps, PhoneNet, Token Ring developed in Zurich, DOS memory limits) — but it pivots into one of the most honest available case studies of LLM-assisted development in a deeply constrained environment, and the lessons are unusually sharp.
• What: The speaker reimplemented the 3Com 3C509B configuration utility (3CCFGCLI) in 16-bit real-mode 8086 assembly, because the original needs a 286+ and 232 KB on disk. The result: 0.8.3 is feature-complete and runs on a real 8086 in ≤256 KB RAM, with the binary refactored from 40 KB down to 26 KB.
• How: Used an LLM as "a very fast, sometimes hallucinating developer" — not an oracle. Concrete episodes: the LLM correctly suggested a full hardware mock early, the speaker refused, and paid for it with an entire 0.6 refactoring branch; separately, the LLM burned three hours chasing a "mysterious" 1-byte offset down into disassembling Turbo Assembler itself when the root cause was that 8086 short jumps can only reach ±127 bytes and the routine had simply outgrown them. Discipline: the ~180-case test harness was human-built, all output reviewed, and continuous refactoring kept the bloat down.
• Where applicable: As engineering-method takeaways, broadly — "AI can help you build it, but you still need to understand it, review it, and prove that it works." Published at github.com/gpdm/TPC-3CCFGCLI. Only the LLM-methods half generalizes; the vintage-hardware half is for fun (and the ENTER Technikwelt exhibit).