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Agharta Network Upgrade Adopts Constantinople/Petersburg

Ethereum Classic activated Agharta at block 9,573,000 on January 12, 2020, adding bitwise shifting, CREATE2, and EXTCODEHASH.

ETC Community
Ethereum Classic Community
3 min read

Ethereum Classic activated the Agharta network upgrade at block 9,573,000 on January 12, 2020, implementing Ethereum's Constantinople and Petersburg features. Agharta was specified in ECIP-1056.

Included EIPs

  • EIP-145 (Bitwise Shifting Instructions): Added native SHL (shift left), SHR (logical shift right), and SAR (arithmetic shift right) opcodes. Before Agharta, bit shifting required expensive arithmetic (MUL/DIV with powers of 2) at 5+ gas. Native shifts cost 3 gas and enable efficient binary data manipulation.
  • EIP-1014 (CREATE2): Deploys contracts at deterministic addresses calculated as keccak256(0xff, deployer, salt, bytecode_hash). The address is known before deployment, enabling counterfactual instantiation: contracts can be referenced before they exist on-chain. Foundation for state channels, factory patterns, and governance contracts.
  • EIP-1052 (EXTCODEHASH): Returns the keccak256 hash of an account's code in a single opcode (700 gas flat). Previously required EXTCODECOPY to copy entire bytecode then hash it: cost scaled with code size. Enables efficient proxy pattern verification and contract identity checks.

Note on EIP-1283

EIP-1283 (net gas metering for SSTORE) was not included. Ethereum itself removed EIP-1283 in the Petersburg fork after a reentrancy vulnerability was discovered. The SSTORE rebalancing was later reintroduced safely as EIP-2200 in the Phoenix upgrade (ECIP-1088).

Client Requirements

  • Multi-Geth v1.9.6 or later (the client now named Core-Geth)
  • Hyperledger Besu with ETC Agharta support

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