S.DELAY+S.DELAY — signal-flow flowchart

S.DELAY+S.DELAY — signal-flow flowchart

Image rep algo 65 · slots 65 · unit 0 (I-RAM load 84) · family delay · confidence high.

single delay + single delay (dual mono)

68 words, 16 class-A coefficient multiplies (16 named), 0 instructions still opaque, 7 of 68 not yet decoded. Landmarks detected: 5 DRAM read/write word(s).

flowchart TD
    N0["Stereo input (L / R)"]
    N1["External delay line (DRAM)<br/>5 read/write word(s) (880.1.60 = READ, 880.1.20 = WRITE)"]
    N0 --> N1
    N2["controls: DELAY1 DRY/WET, DELAY L, DELAY R, FEEDBACK L, FEEDBACK R, DELAY2 DRY/WET, DELAY L, DELAY R, FEEDBACK L, FEEDBACK R"]
    N1 -.-> N2
    N3["VOLUME<br/>output level"]
    N1 --> N3
    N4["REV SEND<br/>to reverb bus"]
    N3 --> N4
    N5["Output (RETURN to kernel epilogue)"]
    N4 --> N5

    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,N5 io;
    class N1 inferred;
    class N2,N3,N4 ctrl;

Classic-topology match

Most likely textbook topology: Feedback / multi-tap delay line (Schroeder delay).

External delay-DRAM (class-1 ESCAPE word, addr8 bit 6 = write vs read) + a feedback-gain MAC; multi-tap = one write / N read taps.

Instruction hint: class-1 ESC words are the delay taps; delay length = READ_CELL − WRITE_CELL (descriptor); feedback/mix gain = a class-A MAC on the delay-read register SRC 0x0B (LIVE: coef 0.5 = the documented 0.5 mix).

UI parameters (MEASURED, notes/kn5000-dsp-paramlist.md): DELAY1 DRY/WET, DELAY L, DELAY R, FEEDBACK L, FEEDBACK R, DELAY2 DRY/WET, DELAY L, DELAY R, FEEDBACK L, FEEDBACK R, VOLUME, REV SEND.

Per-instruction detail: ../disasm/prog65_s_delay_s_delay.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/.