The October 2015 prototype where the Transfer event gained its indexed parameters, the form ERC-20 later required. Supply 10,000, never used.
Historical Significance
This is where the Transfer event in the October 2015 run that first brought balanceOf, transfer and the Transfer event together on Ethereum mainnet took the shape ERC-20 would require: both address parameters marked indexed, so a transfer can be filtered by sender and by recipient. Every earlier build in the run declares Transfer(address _from, address _to, uint256 _value) with no indexed keyword, which forces an observer to read and decode every log the contract emits to find a transfer. Marking the addresses indexed is what makes a token balance watchable offchain, and it is why a wallet or an explorer can follow a token without executing anything. Deployed in block 448,848 on 27 October 2015, twenty three days before ERC-20 was proposed as ethereum/EIPs issue #20 on 19 November 2015.
Context
Ethereum's Frontier network went live on 30 July 2015. Contracts were compiled and deployed from the geth console, there was no test network in common use, and the material people copied from was the ethereum.org tutorials, the Solidity documentation and the go-ethereum wiki. Almost everything deployed in these months is somebody trying the tools.
Token Information
Key Facts
Description
Deployed 27 October 2015 at 17:47 UTC by 0xB1a2B43A7433dd150BB82227eD519Cd6b142d382, six hours after 0x27Cb40ce7EB4d078196923d608Eb903A17E0C0ED. The single change is the event declaration: Transfer(address indexed _from, address indexed _to, uint256 _value), which moves both addresses into log topics and makes transfers filterable by either party. That change alone takes the runtime from 625 bytes to 611. Public balances mapping, balanceOf read function, transfer returning false on an insufficient balance, no constructor argument so the supply is the default 10,000. Its only transaction is its creation. Source recovered by compiling against solc v0.1.6+commit.d41f8b7c with the optimizer off, reproducing both the deployed runtime and the creation bytecode exactly.
Source Verified
Heuristic Analysis
The following characteristics were detected through bytecode analysis and may not be accurate.
Frontier Era
The initial release of Ethereum. A bare-bones implementation for technical users.
Bytecode Overview
Verified Source Available
Source verified through compiler archaeology and exact bytecode matching.
View Verification ProofShow source code (Solidity)
// Submitted by EthereumHistory (ethereumhistory.com)
contract MyToken {
mapping (address => uint) public balances;
event Transfer(address indexed _from, address indexed _to, uint256 _value);
function MyToken(uint supply) {
if (supply == 0) supply = 10000;
balances[msg.sender] = supply;
}
function transfer(address _to, uint256 _value) returns (bool success) {
if (balances[msg.sender] < _value) return false;
balances[msg.sender] -= _value;
balances[_to] += _value;
Transfer(msg.sender, _to, _value);
return true;
}
function balanceOf(address _owner) constant returns (uint256 balance) {
return balances[_owner];
}
}External Links
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