Foundation
Fork 556759/556760: Bitcoin Parent and Legacy Mainnet Records
Explains why 556759 and 556760 appear together in the Bitcoin 10th anniversary fork description and separates the criteria to avoid mixing with the current mainnet.
The most confusing part in the BTCMobick legacy ledger explanation is 556759 and 556760. The precise expression is that Bitcoin mainnet block 556759 is shared as the parent, and the first fork block of the BTCMobick legacy mainnet is at height 556760.
In fact, 556759 remains a Bitcoin block, while BTCMobick's 556760 should be read as records left in the legacy mainnet transfer site and legacy explorer, not the current mainnet. Since public access to these records cannot be guaranteed indefinitely, the learning screen treats them as separate from the current mainnet for preservation criteria.
Bitcoin mainnet also created its own 556760 block following the same parent block. Therefore, just saying '556760' omits which ledger's 556760 it is and mixes it with the starting point of the current BTCMobick mainnet.
Plain words
First-time terms
- 556759
- The Bitcoin block height used as a reference in the BTCMobick origin explanation.
- Legacy Mainnet
- A name used to distinguish past ledgers and transfer site records before the current mainnet.
- Fork
- The event of diverging into different ledgers after the same reference point.
Learning objectives
- Understand that Bitcoin 556759 is the parent block.
- Understand that BTCMobick legacy mainnet 556760 is not a current mainnet block but a legacy ledger record.
- Learn safe usage criteria for the 556759/556760 notation in public statements.
Parent Block Reference
The Bitcoin mainnet block 556759 hash is 0000000000000000000df0afc4e31685f7ee206bf210972163bcaf5800748bf5.
Since the previous block hash of BTCMobick legacy mainnet block 556760 matches this value, it is accurate to call 556759 the parent block in fork explanations.
Legacy Mainnet Transfer Site Record Reference
The first fork block 556760 hash of BTCMobick legacy mainnet is 000000000031e5a024208c82271d3cd38be831d7655fe46173d4f48040e7900b.
The Bitcoin mainnet block 556760 hash is 00000000000000000030c4519f7f3064e68f28db6e37ddf61b58f70b72da2f68. Since these values differ, blocks after 556760 must be read as different ledgers, and BTCMobick legacy mainnet 556760 should not be read as a current mainnet block.
Verification Model of the Fork Timeline
The fork timeline is not a date chart but a verification model connecting the parent block, post-fork blocks, legacy mainnet, and current mainnet. Each block must include both height and hash.
For deeper inspection, open Bitcoin 556759 and BTCMobick legacy mainnet 556760 simultaneously to check how previous hashes connect. The New Bedford current mainnet is separated as a distinct starting point.
The data collection criterion is not 'same height' but 'same chain.' The timeline sentences include chain name, block height, block hash, and explorer URL together.
Distinguishing Parent Block and Post-Fork Blocks
556759 is read as the Bitcoin parent block that BTCMobick's narrative relies on, and 556760 is read as the block confirmed after the fork in BTCMobick legacy mainnet.
The key is to habitually specify which chain's height is being referred to. Bitcoin 556760 and BTCMobick legacy mainnet 556760 use the same number but are not the same block.
Memory Points
Points to remember
Summarizing 556759 and 556760 in One Line
Bitcoin 556759 is the Bitcoin block shared as the parent of the BTCMobick legacy ledger.
BTCMobick legacy mainnet 556760 is the first post-fork block created on the BTCMobick side following that.
Even though the number 556760 is the same, Bitcoin mainnet 556760 and BTCMobick legacy mainnet 556760 have different hashes and must not be conflated as the same event.
Avoid Mixing Legacy and Current Mainnet
556760 is not the starting point of the current mainnet but a record read from the legacy mainnet transfer site and legacy explorer.
The current mainnet starts anew at height 0 after New Bedford with new rules.
Setting this boundary prevents conflicts between past fork explanations and the ledger descriptions current users see.
Practice
Compare the Two 556760 Blocks
- Find the Bitcoin mainnet block 556760 entry on the source page.
- Find the BTCMobick legacy mainnet first fork block 556760 entry and classify it as a legacy mainnet transfer site record.
- Compare the hashes and previous block hashes of both entries, then place the current mainnet height 0 on a separate line.
Learners can separately refer to 'Bitcoin parent 556759 / BTCMobick legacy mainnet 556760 from the transfer site / current mainnet height 0'.
Create a Comparison Table of the Two Chains' 556760 Blocks
- Write Bitcoin 556760 and BTCMobick legacy mainnet 556760 as two rows.
- Create columns for chain name, height, hash, and previous hash for each row.
- Write reasons why the same height number alone cannot indicate the same block.
Learners can explain fork boundaries by chain and hash relationships rather than by height numbers.
Key takeaways
- 556759 is a safe reference pointing to the shared parent block.
- BTCMobick legacy mainnet 556760 is a record left in the legacy mainnet transfer site and legacy explorer, not the current mainnet.
- Historical statements reduce misunderstandings when ledger name, height, hash, and current mainnet status are noted together.
- Fork boundaries should be read by chain name and hash connections rather than height numbers alone.
Quiz
Quiz
How should 556759 be remembered in this curriculum?
Why must we be careful even if the number is the same 556760?
How is BTCMobick legacy mainnet 556760 treated in the current mainnet?
Evidence and statusSources connected
This localized lesson keeps the same source IDs as the Korean curriculum. Use the source library for ledger checks and official references.
- claim-mobick-origin-fork
- claim-fork-height-sensitive
- claim-current-mainnet-boundary