From transistors
to transformers.

A decoder-only transformer built from scratch in PyTorch — causal self-attention, pre-norm LayerNorm, GELU, and learned positional embeddings — that learns to generate Python source code character by character. No black-box libraries; the attention math is hand-written.

A tiny 32-bit operating system written in C — bootloader, kernel, filesystem, graphics, and syscalls — that boots on QEMU. It ships with its own in-OS C compiler (cc): write C inside the OS, compile it, and run the binary. Systems programming end to end.

Digital logic built up from first principles — from NAND/NOR gates to multiplexers, decoders, parallel adders, latches, and a working ALU with an instruction reader. The physical foundation everything above is standing on.