Build Log

What we built, when, and what we proved.

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May 16, 2026 — Day 1

Phase 1: SIMD + Emscripten Upgrade

Forked nbarkhina/N64Wasm (MIT) → wbaxterh/n64-wasm

The big change — 3 Makefile flags:

- -DNOSSE          # Was DISABLING all SIMD
- -DNO_ASM         # Was disabling assembly optimizations
+ -DARCH_MIN_SSE2  # Enables SSE2 codepaths in RSP vector unit
+ -msimd128        # WASM 128-bit SIMD
+ -mrelaxed-simd   # Relaxed SIMD for extra perf
+ -msse -msse2     # Emscripten SSE2 compat headers

Emscripten upgrade: 2.0.7 (2021) → 5.0.7 (2026) — required fixing:

• gzFile pointer types in libretronew.c
• Implicit int in pif.c and emulate_game_controller_via_libretro.c
• EXTRA_EXPORTED_RUNTIME_METHODS → EXPORTED_RUNTIME_METHODS

Result: 11,979 SIMD instructions in the output binary. THPS running at 60 FPS.

N64 USB Controller Support

Discovered the upstream N64Wasm had:

• No Joypad mapping UI for C-buttons
• No remap handler for C-button joypad (cases 13-16 missing in remapPressed())
• Default button mappings for Xbox/PS controllers (wrong for N64 USB adapters)

Fixed: Added Joypad remap UI + handler for all C-buttons. Mapped actual N64 USB adapter:

A=btn6, B=btn8, Z=btn7, Start=btn9
L=btn4, R=btn5
C-Up=btn0, C-Down=btn2, C-Left=btn3, C-Right=btn1
D-pad=btn12-15

Also added axis 2/3 C-button processing for adapters that map C-buttons as analog axes.

UI Redesign

Stripped the Bootstrap 4 generic look. New retro terminal aesthetic:

• Dark background (#0a0a14) with CRT scanline overlay
• Press Start 2P + Orbitron + JetBrains Mono typography
• N64 controller color palette (green, yellow, red, blue, purple)
• All Bootstrap components restyled (modals, forms, tables, buttons, dropdowns)
• New header: "N64.wasm — SIMD-Powered Browser Emulator"
• New footer: TrickBook + GitHub + Docs links

Gamepad Auto-Detect Wizard

Built gamepad-wizard.js — interactive controller mapping:

1. Detects gamepad via Gamepad API gamepadconnected event
2. Prompts "Controller Detected — Map Buttons / Skip"
3. Walks through all 14 N64 inputs: A, B, Z, Start, L, R, C-pad, D-pad
4. Prevents duplicate button assignments
5. Saves to localStorage for persistence across sessions
6. Shows completion summary before saving

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Phase 2: NextJS + React Component

Created wbaxterh/n64-web — NextJS 16 app:

• N64Emulator React component (client-side only via dynamic())
• GamepadStatus component (connection indicator)
• COOP/COEP headers in next.config.ts (SharedArrayBuffer ready)
• /play route with drag-and-drop ROM loading
• Keyboard controls reference (collapsible)
• Retro terminal theme matching docs site

Deployed to play.weshuber.com via AWS Amplify:

• GitHub → Amplify CI/CD (auto-builds on push to master)
• SSL certificate (Amplify managed)
• Route53 CNAME → CloudFront

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Infrastructure Created

Resource	Details
wbaxterh/n64-wasm	WASM core repo (forked, SIMD-enabled)
wbaxterh/n64-web	NextJS app repo
wbaxterh/n64-docs	This docs site
play.weshuber.com	Emulator app (Amplify)
n64.weshuber.com	Documentation (Amplify)
Emscripten 5.0.7	Installed at ~/emsdk