Computing from the ground up
Bit
Root
A growing field guide. Real Rust and C code. Three depth levels on every page: beginner, intermediate, advanced.
From electrons switching states to UTF-8 encoding the emoji in your text. Every topic builds on the one before it.
Building BitRoot in public. New topics drop here first, plus the research, the weird CS rabbit holes, and the threads that distill each page into 60 seconds.
Follow on XDecimal, binary, octal, hex, plus the weirder ones. Why programmers move between bases, and how.
02 / BINARYBinaryTwo symbols. Infinite meaning. Counting, shifting, two's complement, IEEE 754 floats.
03 / ASCIIASCIIThe agreement that turns bit patterns into language. 7-bit ASCII, control codes, and the leap to UTF-8.
04 / LOGIC GATESLogic GatesThe physical switches that are the bits. CMOS transistors, NAND universality, adders.
05 / CPUCPUWire it all together. Fetch-decode-execute, registers and ALUs, pipelines, caches, branch prediction.
06 / MEMORYMemoryWhere state lives. RAM vs ROM, stack vs heap, virtual memory, and how Rust, C and GC'd languages manage it.
07 / OPERATING SYSTEMOperating SystemOne CPU, hundreds of programs. Kernel vs user mode, syscalls, processes, threads, schedulers, virtual memory.
08 / VARIABLESVariablesWhat `let x = 42` actually does. Stack vs heap, primitive vs dynamic, alignment, and lifetime, in Rust and C.
09 / POINTERSPointersA number that means somewhere. Why pointers power every data structure, and the five classic bugs. C raw pointers vs Rust ownership.
10 / COMPILE VS RUNTIMECompile vs RuntimeTwo phases of every program. What gets decided when, why pushing work earlier matters, and how the split shows up in every layer above.
11 / ARRAYSArraysHouses on a numbered street. Contiguous memory, O(1) indexing, cache locality, and the structure underneath every other data structure.
12 / LINKED LISTLinked ListA chain of nodes, each one pointing at the next. The data structure that trades cache locality for cheap inserts, and the one every other pointer-y structure is built from.
13 / HASHINGHashingA fingerprint for anything. Hash functions, hash maps, collision handling, cryptographic hashes, Merkle trees, and the chain in blockchain.
14 / NODESNodesOne word, three scales. A node in a data structure, a node on a network, a node in a blockchain. The same essential pattern, applied from bytes to billion-dollar systems.
15 / NETWORKINGNetworkingWhere one machine becomes many. IP addresses, packets, TCP/IP, routing, sockets, and why every previous topic shows up the moment two computers talk.
16 / DISTRIBUTED SYSTEMSDistributed SystemsNo single machine knows everything. Many computers, no central authority, eventual agreement. CAP theorem, gossip, Byzantine fault tolerance, and why this is the page right before blockchain.
17 / CAP THEOREMCAP TheoremYou can only guarantee two. Consistency, availability, partition tolerance: pick any two. The silent tradeoff every database, app, and blockchain quietly made without telling you.
18 / PACELCPACELCCAP told you what breaks. PACELC tells you what you choose every second. Latency vs consistency on every request, even when the network is perfectly healthy.
19 / BLOCKCHAINBlockchainThe capstone. From one transistor in 1947 to a financial network nobody owns. How every previous topic stacks into Bitcoin, end to end, with nothing missing.
20 / RECURSIONRecursionA function that calls itself, until it doesn't. The most elegant idea in programming and the fastest way to crash a server. The base case is survival.
21 / BIG O NOTATIONBig O NotationSame answer, 317 years apart. Big O is not about speed, it is about how code scales. The lens that makes the whole curriculum coherent, from arrays to Bitcoin's security.
The abstraction stack (reading order)