NeoOpenComputers

Java-first community port of MightyPirates/OpenComputers to Minecraft 1.21.1 on NeoForge.

The project name intentionally differs from the original mod: NeoOpenComputers identifies this as a newer NeoForge-focused port.

Current State

This repository is an active Java-first NeoForge 1.21.1 port. It intentionally does not compile the old Scala implementation. The old mod is used as a behavioral reference while systems are ported incrementally.

Current pushed first-smoke base:

• Latest pushed develop.
• The Obsidian port dashboard records the exact last verified commit and verification timestamp.

Current verification evidence:

• Unit/build gate: .\gradlew.bat test build --no-daemon --console=plain
• GameTest gate: .\gradlew.bat runGameTestServer --no-daemon --console=plain
• Latest GameTest result: 428/428 required tests passed.
• Bounded client launch smoke reaches resource reload and texture atlas creation without NeoOpenComputers-owned missing model, missing texture, or mod loading errors.
• MCP evidence shows tier 2 and tier 3 screens open their terminal GUI after a fresh client restart. World-render screenshot proof for tier 2 and tier 3 screens is still pending, so screen visuals are not treated as verified alpha evidence yet.

The port has broad API, machine, network, filesystem, terminal, screen/GPU/input, modem/redstone, storage, inventory/tank/transposer, rack/server, nanomachine, printer, print, manual, player-facing failure feedback, and packaging slices in place. It is ready for first technical alpha testing, not stable-release-ready.

Robots, drones, and block microcontrollers are not available in this alpha build. Microcontroller case items are present for recipe/API compatibility only and are not alpha smoke targets. Computer cases, servers, racks, screens, keyboards, storage, cards, and upgrades are the current alpha focus.

See the First Alpha Testing Guide for the current install, smoke-test, known-gap, and issue-reporting checklist. See the Alpha Smoke Matrix for evidence mapping, Alpha Release Checklist for first-alpha handoff gates, Visual Smoke Runbook for screenshot proof, Screen Work Protocol for the anti-loop screen evidence gate, Alpha Finding Template and the GitHub Alpha finding issue form for reproducible issue reports, Contributing for community development rules, and Changelog for alpha scope notes.

GitHub Actions are intentionally disabled until the mod is ready enough for CI. Do not add .github/workflows yet.

Chosen upstream reference branch:

• master-MC1.12

Reason: it is the newest useful maintained OpenComputers line. The branch still targets Minecraft 1.12.2, but it has newer maintenance and build tooling than the misleading master-MC1.16 branch.

Requirements

• JDK 21
• Git
• Gradle wrapper included in this repository

Build

.\gradlew.bat build

The built mod jar is written to build/libs.

Install build/libs/neoopencomputers-0.1.0.jar for smoke testing. This jar includes the bundled runtime libraries. Do not install neoopencomputers-0.1.0-thin.jar; it is the developer thin jar and does not include bundled runtime libraries.

Run Development Client

.\gradlew.bat runClient

First Technical Smoke Test

Use this for local crash finding and first in-world proof. This is not a community beta checklist.

1. Build the jar:

.\gradlew.bat test build --no-daemon --console=plain

2. Run GameTests:

.\gradlew.bat runGameTestServer --no-daemon --console=plain

3. Start the development client:

.\gradlew.bat runClient --no-daemon --console=plain

Restart the Minecraft client after replacing the mod jar; a running JVM keeps the old jar loaded.

Verify the installed jar hash matches the built jar hash after copying, before launching Minecraft:

$built = Get-FileHash .\build\libs\neoopencomputers-0.1.0.jar -Algorithm SHA256
$profileRoot = Join-Path $env:APPDATA "ModrinthApp\profiles\<profile-name>"
$installedPath = Join-Path $profileRoot "mods\neoopencomputers-0.1.0.jar"
Copy-Item .\build\libs\neoopencomputers-0.1.0.jar $installedPath -Force
$installedAfter = Get-FileHash $installedPath -Algorithm SHA256
if ($built.Hash -ne $installedAfter.Hash) {
    throw "Installed NeoOpenComputers jar hash does not match the built jar hash after copying."
}

4. In a local test world, check these flows:

• Computer case, screen, and keyboard place without crashing.
• Logs show no NeoOpenComputers-owned missing model, missing texture, or mod loading errors. Third-party profile warnings should be recorded separately and only block alpha if they break NeoOpenComputers testing.
• OpenOS/Lua prompt boots.
• Basic filesystem, EEPROM, floppy, and disk-drive actions work.
• Screen output and keyboard input survive save/reload.
• Terminal item key input, paste, mouse click/drag/release, and scroll reach the bound computer.
• Computer case hard-disk data survives save/reload.
• Disk-drive floppy data survives save/reload.
• Power and charging smoke passes: a computer accepts Forge Energy or runs from a powered OC network, and one chargeable item accepts charger energy.
• Redstone, modem, inventory, tank, and transposer each get one basic smoke pass.
• Texture picker reports usable atlas texture names such as minecraft:block/stone.
• Printer creates a print item.
• Print item visually uses configured shape data.
• Placed print rotates, renders configured shape data, drops configured data, handles button-mode redstone activation, held-item activation, beacon-base setting, tooltip data, opacity setting, and legacy texture names.

5. Save logs and screenshots for any crash, missing texture, client/server error, or unexpected visual behavior.

For every first-smoke finding, include:

• NeoOpenComputers jar version or commit.
• Jar SHA256.
• current jar install timestamp.
• Crash report timestamp.
• Crash report path or full crash log.
• Client log section around the failure.
• Screenshot or short video for visual bugs.
• Exact steps to reproduce in a fresh world when possible.

Run Development Server

.\gradlew.bat runServer

On first server run, accept the generated EULA in the run directory.

Porting Approach

1. Keep NeoForge 1.21.1 project Java-only.
2. Port OpenComputers systems in small slices from master-MC1.12.
3. Keep li.cil.oc.api for source compatibility where practical.
4. Start with stable contracts and internal model code before UI and integrations.
5. Re-add optional mod integrations only when current 1.21.1 APIs exist.

Licensing

This port is MIT licensed. Original OpenComputers code is MIT licensed by Florian "Sangar" Nücke and contributors. Keep upstream notices and third-party license files when porting code, assets, Lua runtimes, or bundled libraries.

The NeoForge MDK template license remains in TEMPLATE_LICENSE.txt.