[ANN] Bitcoin Coin Series (Half/Quarter/Dime/Nickel/Cent) | CPU, no premine

[sentodaimon]

Bitcoin Coin Series (Half / Quarter / Dime / Nickel / Cent)
CPU-mined Bitcoin forks | no premine | mainnet live since 2026-11-06

Bitcoin Coin Series is an experimental, unofficial set of five Bitcoin Core forks. It is not affiliated with Bitcoin, Bitcoin Core or any Bitcoin organization.

Why

Bitcoin's supply is fixed at 21 million. As its value grows, one coin moves further away from everyday amounts: a cup of coffee is 0.000034 BTC. Sub-units like satoshis are one answer. This project tests a different one: five separate coins with different unit sizes (1/2, 1/4, 1/10, 1/20 and 1/100 of a bitcoin, like US coins). All five start at the same moment under the same rules, are mined together on ordinary computers and are given free to existing bitcoin holders. The question is simple: given the same start, how do people take up and use different units?

It is a long-running experiment, not a business. It does not compete with Bitcoin. The fair start (genesis tied to a future Bitcoin block, no premine) exists so that the experiment is not distorted by insiders, including me.

The five coins

Coin	Ticker	Multiplier	Max supply
Bitcoin Half	BTCH	x2	42,000,000
Bitcoin Quarter	BTCQ	x4	84,000,000
Bitcoin Dime	BTCD	x10	210,000,000
Bitcoin Nickel	BTCN	x20	420,000,000
Bitcoin Cent	BTCC	x100	2,100,000,000

What it is

• Bitcoin Core v31.1 plus 11 small patches. All source patches are in the repository.
• Proof of work is RandomX v1, so it is mined on ordinary CPUs. One computation mines all five chains at once (merged mining).
• A block every 10 minutes. Difficulty adjusts every block, with stall relief if no block is found for an hour.
• Block rewards follow Bitcoin's schedule from height 840,000, times the multiplier.
• Bitcoin holders at block 840,000 can claim the multiplied amount by signing with their own keys (BIP-322 or legacy signed message). A claim never moves bitcoin.
• Signatures include a chain identifier, so transactions cannot be replayed between chains or onto Bitcoin.

Fair start and honest status

• The genesis of each chain contains the hash of Bitcoin block 974800, which did not exist when the code was published. Nobody, including the issuer, could mine before that block appeared.
• No premine and no developer allocation. There was no presale or fundraising, and the issuer does not sell coins or promise any price. Anyone who mines or claims coins is free to use or exchange them as they wish.
• The mainnet launched on 2026-11-06. So far the issuer has been the only miner, at about 1,300 H/s on one desktop PC. All of the roughly 900 blocks so far (as of 2026-11-13) were mined by the issuer, for example about 5,600 BTCH. The issuer's reward addresses are listed in the README, so anyone can check them. Every new miner makes the chain less dependent on one person. That is the purpose of this post.

How to join (Windows)

• 1. Download the repository and copy the windows folder.
• 2. Download the Bitcoin Core UTXO snapshot of block 840,000 (about 9.8 GB, torrent or direct link in the README). The node checks its hash, so the source does not matter.
• 3. Run m1-start-mainnet.bat. It connects to the public node coinseries.duckdns.org, syncs and starts mining with all CPU threads.

Tested on a fresh laptop: from first run to mining took about 15 minutes, excluding the download.
Linux and other systems: build Bitcoin Core v31.1 with the patches in patches/.

Public node (all five chains): coinseries.duckdns.org, ports 21302 (Half), 21304 (Quarter), 21310 (Dime), 21320 (Nickel), 21400 (Cent).

Please note

• This is an experiment. The coins have no promised value and there is no exchange listing.
• To claim, sign a message in your own wallet. Never type a private key or seed phrase into any website or tool, including anything claiming to be from this project.

Repository: https://github.com/sentodaimon/coin-series
Specification, whitepaper (English and Korean) and manual are in docs/.

Questions and test reports are welcome in this thread.

- Sento Daimon

[drywall777]

Hello.  I've downloaded the bundle and successfully started mining all 5 coinseries. I've even landed some blocks.  I don't have a lot of skills, so I'm a bit confused as to how we would open each wallet, and in the future, be able to send coins.  Also, I'm wondering how a person could restore one or all of the wallets.
Thanks for your time.

[sentodaimon]

Status update (2026-11-15)

• External miners joined on 2026-11-13, about 20 minutes after this post. Thank you.
• Height 1,376. Network hash rate about 36,000 H/s (the issuer alone: about 1,300 H/s). Block intervals returned to about 10 minutes after the difficulty adjusted. No reorganizations so far.
• Last 100 blocks by reward address: 58, 34 and 3 from three external addresses, 5 from the issuer. The largest address has more than half of the hash rate, so more miners would make the chain healthier.
• Live status page, updated every 10 minutes: https://sentodaimon.github.io/coin-series/

Claims for Bitcoin holders

• New step-by-step guide: docs/claim-guide.md in the repository.
• New helper tools/cs_claim_psbt.py: the claim can be signed as a PSBT in an ordinary wallet, so wallets without BIP-322 message signing work too. The private key never leaves your wallet and the PSBT cannot move bitcoin.
• Tested end to end on regtest with a Bitcoin Core wallet for 1..., 3..., bc1q... and bc1p... addresses on all five coins (tools/psbt_claim_test.sh). No mainnet claim has been made yet; first reports are welcome in this thread.

Notices

• The public node coinseries.duckdns.org will be offline for about half a day on 2026-12-06 (moving). The chain continues with the other miners.
• Windows 11: if Windows reports that an application control policy blocked bitcoind.exe or bitcoin-cli.exe, Smart App Control is on. The kit binaries are not code-signed. Building from source with the patches is the alternative.

- Sento Daimon

[sentodaimon]

I don't have a lot of skills, so I'm a bit confused as to how we would open each wallet, and in the future, be able to send coins.  Also, I'm wondering how a person could restore one or all of the wallets.

Thanks for mining and for the question. There is no graphical wallet yet; each coin has its own wallet named w, used through bitcoin-cli. Open a Command Prompt in the windows folder of the kit (where bitcoin-cli.exe is) and use the commands below. They are for Half; for the other coins change -coin=half to quarter, dime, nickel or cent. If you changed DATA in m0-settings.bat, use that folder instead of C:\CoinSeries\mainnet.

1. Protect and back up first
Run m2-protect-wallets.bat. It sets one password on all five wallets and saves a copy of each wallet to C:\CoinSeries\mainnet-backup (half-wallet.dat, quarter-wallet.dat, ...). Write the password on paper and copy that folder to a USB stick. Without the password the coins cannot be spent, and nobody can recover it.

2. See your balance

Code:

bitcoin-cli -datadir=C:\CoinSeries\mainnet -chain=main -coin=half -rpcwallet=w getbalances

Mining rewards show as "immature" first and become spendable after 100 blocks (about 17 hours). m3-status.bat shows this for all five coins.

3. Receive

Code:

bitcoin-cli -datadir=C:\CoinSeries\mainnet -chain=main -coin=half -rpcwallet=w getnewaddress

4. Send
Unlock for 60 seconds (only needed after m2), then send:

Code:

bitcoin-cli -datadir=C:\CoinSeries\mainnet -chain=main -coin=half -rpcwallet=w walletpassphrase "your password" 60
bitcoin-cli -datadir=C:\CoinSeries\mainnet -chain=main -coin=half -rpcwallet=w sendtoaddress hf1q... 1.5

Each coin only accepts its own addresses (hf1 Half, qt1 Quarter, dm1 Dime, nk1 Nickel, ct1 Cent), so coins cannot be sent to the wrong chain by mistake.

5. Restore
On any PC with the node running (same coin), restore a backup file under a new wallet name:

Code:

bitcoin-cli -datadir=C:\CoinSeries\mainnet -chain=main -coin=half restorewallet w2 "D:\backup\half-wallet.dat"

Then use -rpcwallet=w2 in the commands above, with the same password. Repeat for each coin with its own backup file. The node rescans the chain, so restored balances appear after it finishes.

Keep the backup files private: anyone with a backup and its password can spend the coins.

[drywall777]

Thank you!