GATED REVERB — signal-flow flowchart

Image rep algo 8 · slots 8 · unit 0 (I-RAM load 84) · family reverb · confidence medium.

gated reverb: all-pass ring + hold gate

102 words, 22 class-A coefficient multiplies (7 named), 0 instructions still opaque, 8 of 102 not yet decoded. Landmarks detected: 2 C-format immediate load(s), 10 DRAM read/write word(s), 6 all-pass marker(s).

flowchart TD
    N0["Stereo input (L / R)"]
    N1["External delay line (DRAM)<br/>10 read/write word(s) (880.1.60 = READ, 880.1.20 = WRITE)"]
    N0 --> N1
    N2["controls: HIGH DAMP GAIN"]
    N1 -.-> N2
    N3["All-pass / phaser chain<br/>6 marker(s); g&middot;d &plusmn; feedback (stage count OPEN)"]
    N1 --> N3
    N4["C-format immediate loads (C40/C41)<br/>destination register UNKNOWN &mdash; the old 'envelope detector' reading is WITHDRAWN &times;2"]
    N3 --> N4
    N5["VOLUME<br/>output level"]
    N4 --> N5
    N6["REV SEND<br/>to reverb bus"]
    N5 --> N6
    N7["Output (RETURN to kernel epilogue)"]
    N6 --> N7

    classDef io fill:#e8eef7,stroke:#33475b,stroke-width:1px,color:#111;
    classDef proven fill:#d7f0d7,stroke:#2e7d32,stroke-width:2px,color:#111;
    classDef measured fill:#dbe9fb,stroke:#1565c0,stroke-width:1.5px,color:#111;
    classDef inferred fill:#fdf0d5,stroke:#b8860b,stroke-width:1.5px,color:#111;
    classDef open fill:#eeeeee,stroke:#888,stroke-width:1px,color:#333,stroke-dasharray:5 5;
    classDef ctrl fill:#f3e8fb,stroke:#6a1b9a,stroke-width:1px,color:#111;
    class N0,N7 io;
    class N1,N3 inferred;
    class N2,N5,N6 ctrl;
    class N4 open;

Classic-topology match

Most likely textbook topology: All-pass diffuser ladder + comb (Schroeder/Moorer reverb tank).

A chain of all-pass sections (single coefficient/stage on the KN5000) over the external delay-DRAM — the most DRAM-heavy program; ER taps at 6000/12000/18000/24000 samples.

Instruction hint: the diffuser feed/feedback gains are class-A MACs on delay-read taps; the all-pass z⁻¹ updates are the bqp pair (ACT 0x0D/0x0E).

UI parameters (MEASURED, notes/kn5000-dsp-paramlist.md): GATE TIME, HIGH DAMP GAIN, THRESHOLD, MASK TIME, VOLUME, REV SEND.

Per-instruction detail: ../disasm/prog08_gated_reverb.dsm. Confidence legend and method: README.md. Narrative: the MAME development blog, KN5000 effects-DSP series (Parts 78-84). Reference: the project docs site, /effects-dsp/.