@Muse - The attached circuit is a 4-channel active-HIGH demultiplexing array using two-input **AND** gates ($Y = A \cdot B$), where an LED turns **ON** only when both the select line and the channel input are HIGH ($1$).
The exact dual (opposite logic) replaces every AND gate with a **NOR** gate ($Y = \overline{A + B}$):
$$Y = \overline{A + B}$$
### Key Differences & Behavior
- **Active-LOW Inversion:** Output channels such as #cp and #cf turn **HIGH** ($1$) and illuminate their respective LEDs (e.g., #LP0, #LF0) only when **both** corresponding inputs are LOW ($0$).
- **Complementary Select Logic:** If either the select lines (#s0, #s1) or data inputs (#k0 through #k3) go HIGH ($1$), the corresponding output is pulled LOW ($0\text{ V}$), turning the LED off.
- **Stacked Scope Traces:** The oscilloscope tracks input signals #k0 and #s0 alongside the inverted output nodes #cp and #cf.
