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Analysis Methodology

How we analyzed 6 major terminal emulators to understand flow control.

Research Overview

┌───────────────────────────────────────────────────────────────────────┐
│  RESEARCH SCOPE                                                        │
├───────────────────────────────────────────────────────────────────────┤
│                                                                        │
│  Terminals Analyzed:                                                   │
│                                                                        │
│    Alacritty  ────  Rust       GPU-accelerated                        │
│    Ghostty    ────  Zig        Performance-focused                    │
│    WezTerm    ────  Rust       Feature-rich                           │
│    xterm.js   ────  TypeScript Web-based                              │
│    Hyper      ────  TypeScript Electron-based                         │
│                                                                        │
└───────────────────────────────────────────────────────────────────────┘

The Core Question

┌───────────────────────────────────────────────────────────────────────┐
│  WHY DOES MONOTERM STAY STABLE?                                        │
├───────────────────────────────────────────────────────────────────────┤
│                                                                        │
│  During high-output LLM streaming:                                     │
│                                                                        │
│    Traditional terminals  -->  Jitter, freeze, crash                   │
│    MonoTerm              -->  Stable, smooth output                    │
│                                                                        │
│  Question: What architectural decision makes the difference?           │
│                                                                        │
└───────────────────────────────────────────────────────────────────────┘

5 Research Threads

┌───────────────────────────────────────────────────────────────────────┐
│  PARALLEL ANALYSIS STRUCTURE                                           │
├───────────────────────────────────────────────────────────────────────┤
│                                                                        │
│  THREAD A: Data Input                                                  │
│  ─────────────────────────                                             │
│  How data enters from PTY                                              │
│  Focus: Read mechanisms, threading                                     │
│                                                                        │
│  THREAD B: VTE Parsing                                                 │
│  ─────────────────────────                                             │
│  How bytes become terminal state                                       │
│  Focus: Escape sequences, ANSI handling                                │
│                                                                        │
│  THREAD C: State Management                                            │
│  ─────────────────────────                                             │
│  How terminal state is stored                                          │
│  Focus: Grid structure, damage tracking                                │
│                                                                        │
│  THREAD D: Rendering                                                   │
│  ─────────────────────────                                             │
│  How state becomes pixels                                              │
│  Focus: GPU pipeline, frame timing                                     │
│                                                                        │
│  THREAD E: Flow Control   <── THE KEY                                  │
│  ─────────────────────────                                             │
│  What feedback exists between layers                                   │
│  Focus: ACK mechanisms, backpressure                                   │
│                                                                        │
└───────────────────────────────────────────────────────────────────────┘

Thread E: The Critical Finding

┌───────────────────────────────────────────────────────────────────────┐
│  FLOW CONTROL COMPARISON                                               │
├───────────────────────────────────────────────────────────────────────┤
│                                                                        │
│    Terminal       Flow Control         Render Feedback                 │
│    ──────────     ────────────────     ────────────────                │
│    Alacritty      Lock-based                 X                         │
│    Ghostty        Queue-based                X                         │
│    xterm.js       Buffer watermark           X                         │
│    WezTerm        Time-based                 X                         │
│    Hyper          Inherited (xterm.js)       X                         │
│                                                                        │
│    MonoTerm       ACK Gate                   O   <── Unique!           │
│                                                                        │
└───────────────────────────────────────────────────────────────────────┘

Analysis Output Structure

┌───────────────────────────────────────────────────────────────────────┐
│  DOCUMENTATION DELIVERABLES                                            │
├───────────────────────────────────────────────────────────────────────┤
│                                                                        │
│    Per-Step Analysis:                                                  │
│                                                                        │
│      Thread A  -->  10 documents  (PTY layer)                          │
│      Thread B  -->  10 documents  (Parser layer)                       │
│      Thread C  -->  10 documents  (Grid layer)                         │
│      Thread D  -->  10 documents  (Renderer layer)                     │
│      Thread E  -->  10 documents  (Flow control)                       │
│                                                                        │
│    Summary Documents:                                                  │
│                                                                        │
│      Thread summaries with comparison tables                           │
│      Final synthesis with recommendations                              │
│                                                                        │
└───────────────────────────────────────────────────────────────────────┘

Success Criteria

Each analysis document includes:
┌───────────────────────────────────────────────────────────────────────┐
│  DOCUMENT REQUIREMENTS                                                 │
├───────────────────────────────────────────────────────────────────────┤
│                                                                        │
│    1. Mechanism Description                                            │
│       How the component works                                          │
│                                                                        │
│    2. Flow Control Assessment                                          │
│       None / Partial / Full                                            │
│                                                                        │
│    3. UX Impact                                                        │
│       Effect on high-output stability                                  │
│                                                                        │
│    4. Cross-Reference                                                  │
│       Related findings in other threads                                │
│                                                                        │
└───────────────────────────────────────────────────────────────────────┘

Key Insight

┌───────────────────────────────────────────────────────────────────────┐
│  THE FINDING                                                           │
├───────────────────────────────────────────────────────────────────────┤
│                                                                        │
│    "Deep code analysis reveals the architectural decisions             │
│     that determine UX quality."                                        │
│                                                                        │
│                                                                        │
│    All 6 terminals analyzed:                                           │
│                                                                        │
│      NONE provide render-synchronized flow control                     │
│                                                                        │
│    Only MonoTerm:                                                      │
│                                                                        │
│      Consumer (frontend) controls producer (backend) rate              │
│      via ACK handshake after successful render                         │
│                                                                        │
└───────────────────────────────────────────────────────────────────────┘