OSBTC

Old School Bitcoin

One CPU, one vote.

Bitcoin's 2009 rules, unchanged: 21 million coins, 50 per block, halving every 210,000 blocks. Only the mining algorithm is new, so the computer you already own is the miner.

Mainnet launches Saturday 31 October 2026, 8:00 pm Eastern

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Why OSBTC

Bitcoin's rules

Same supply cap, same halvings, same 10-minute blocks, same scripts and transactions. Anything you know about Bitcoin carries over.

CPU-first mining

OSHash-Y needs a 2 MiB scratchpad per hash, which fits a desktop CPU and punishes GPUs and ASICs. Early GPU tests came out at roughly 6x worse per dollar than CPUs.

No premine

Every coin comes from mining. The genesis block pays nothing to anyone, and there is no dev fund and no insider allocation.

The numbers

Ticker
OSBTC
Max supply
21,000,000
Block reward
50 OSBTC
Halving
every 210,000 blocks
Block time
10 minutes
Difficulty retarget
every 2,016 blocks
Proof of work
OSHash-Y
Premine
none

Genesis message: Old School Bitcoin 28/Sep/2026 One CPU, one vote

Mainnet genesis hash:
621b58c55a49bbacdbc9cb5192f47638b6aa03d9ac04747f3d291131d0945179

OSHash-Y mining

OSHash-Y chains three audited, unmodified primitives: SHA-256d, yespower 1.0 (N = 2048, r = 8) and SHA3-256. Nothing exotic was invented, so there is little new to break. Block and transaction IDs stay Bitcoin's.

  1. Run a nodeWallet and full node for Windows, macOS, Linux and Android ship at launch.
  2. Point a CPU miner at itA cpuminer build with the oshash algorithm will be published with the release.
  3. Earn 50 OSBTC per blockA pool will be open from day one for smaller machines.

Solo first

For the first weeks, OSBTC is meant to be mined directly from your own laptop or desktop, with the miner talking to your own node. No account, no pool, no rental marketplace. A short, solo-friendly start spreads the first blocks across many people instead of a few big operators.

Pool support opens after the first difficulty adjustment (block 2,016). The date is announced here.

An open start

Mainnet starts at difficulty tuned for a handful of CPUs, and nobody can mine a valid block before launch: the genesis is stamped with the launch time and nodes reject blocks from the future. Release files, seed nodes and pool details are published here when the countdown ends, so everyone starts together.

OSBTC is new software and has not had an external security review. Mine and hold only what you can afford to lose.