Mr. Chatterbox, or, The Modern Prometheus

While I do not have a technical background, I am very fortunate to live in the era of Andrej Karpathy's nanochat, a very simple harness for training LLMs, and Claude Code, a tool for those who, like me, know just enough Python to know how to break things but not enough to know how to fix them. I am not a machine learning expert or AI lab with gobs of money. My only co-worker can't speak English and spends most of the day sleeping on my lap or cleaning her fur. I'm just a man with a laptop, Claude Code, and a dream of the 1890's.

happened to stumble across the British Library Books dataset, a dataset of digitized books dating from between 1500 and 1900

This left me with 28,035 books, or roughly 2.93 billion tokes for pretraining data

I settled on using a Vast.ai instance that used PyTorch. Renting a NVIDIA H-100 GPU ran me between $1.50 and $2.00 per hour.

Using Claude Code, I trained a BPE tokenizer from scratch on the corpus, ending up with a vocabulary of about 32,000 words. Using a modern tokenizer wouldn't capture the unique Victorian morphology and orthography of the corpus.

However, my method for dealing with most other problems was to nicely ask Claude Code to fix them once identified, and it was able to without too many issues.

the final pre-trained model came out to about 340 million parameters, and had a final validation bpb of 0.973. The pretraining process took about five hours on-chip, and cost maybe $35. I had my pretrained model, trained in 6496 steps

but it lacked the spark of intellect that would allow such a creation to engage in discourse. I needed to develop some kind of dataset to teach it the art of conversation

Fortunately, I already had a corpus of 28,000 books, so I set Claude Code to work extracting dialogue pairs from the books. I ultimately ended up with 190,000 or so training pairs. So, when one person said X, I had an example of another person saying Y. The art of conversation!

I needed to rewrite these corpus pairs so that the input question was in modern argot. This task was more than I could possibly do by hand, so Claude Code suggested, helpfully, that I used Claude Haiku to rewrite the input questions

Totally useless. This model—which I will call Model #1—had learned to emit Victorian-sounding novelistic gobbledygook in response to user inputs, not how to answer user queries. I had assumed my pre-written QA pairs were good enough, when they clearly weren't. It was back to the drawing board

I decided to start including fully-synthetic data in the mix. Working with Claude Code, I asked it to write a script that would direct another LLM to write a .jsonl file of fully-synthetic scenes. In them, a user greeted the LLM, queried about Victorian topics, and the LLM responded in a period-appropriate manner for 2-4 turns. We

Or $496.66 all together.