Coin

Utility

0x4d0cd1277c4d...808ec64e6577

FrontierContract #778Exact Bytecode MatchEdit this contract

Deployed September 3, 2015 (10 years ago)Block 180,151

The Solidity tutorial subcurrency, with the balance reader restricted to the minter

Frontier EraVerified Source

Context

Deployed in September 2015 on the Frontier chain.

Key Facts

Deployer

0xee2915...b2a2d2

Deployment Block

180,151

Deployment Date

Sep 3, 2015, 04:24 PM

Code Size

843.0 B

Gas at Deploy

249,678

Deployment Transaction: 0x7fc07b57d9a8bfe8...9103b932c6cde5ed

Description

The Coin example from the August 2015 Solidity Tutorial with one change: queryBalance returns zero to anyone who is not the minter, so only the account that deployed the contract can read balances through it. The change is cosmetic, since every balance is still visible in storage and every transfer still emits a Send event naming both parties, but it shows the author reaching for access control on a read. The rest is the tutorial unaltered: the deployer is the minter, mint creates units, send moves them.

Source Verified

Exact bytecode match(843 bytes)

Compiler: v0.1.3+

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Heuristic Analysis

The following characteristics were detected through bytecode analysis and may not be accurate.

Detected Type: Utility

Frontier Era

The initial release of Ethereum. A bare-bones implementation for technical users.

Block span: 0 — 1,149,999

July 30, 2015 — March 14, 2016

Bytecode Overview

Opcodes843

Unique Opcodes91

Jump Instructions23

Storage Operations13

Verified Source Available

Source verified through compiler archaeology and exact bytecode matching.

Verified on Etherscan

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Show source code (Solidity)

// Submitted by EthereumHistory (ethereumhistory.com)
contract Coin {
    address minter;
    mapping (address => uint) balances;

    event Send(address from, address to, uint value);

    function mint(address owner, uint amount) {
        if (msg.sender != minter) return;
        balances[owner] += amount;
    }
    function send(address receiver, uint amount) {
        if (balances[msg.sender] < amount) return;
        balances[msg.sender] -= amount;
        balances[receiver] += amount;
        Send(msg.sender, receiver, amount);
    }
    function queryBalance(address addr) constant returns (uint balance) {
        if (msg.sender != minter) return;
        return balances[addr];
    }
    function Coin() {
        minter = msg.sender;
    }
}