Digital Electronics Bench
555 astable timing forward and in reverse (design mode), a Boolean engine that builds truth tables and proves expression equivalence, the resistor color code decoded with live bands, and capacitor three-digit codes. Covers §20.0 and §21.A–C.
Astable 555: Analyze
Truth Table & Equivalence Prover
Variables A–D; NOT is a postfix apostrophe (A'), AND is · or adjacency (AB), OR is +. Constants 0, 1. Leave the second expression blank for a table only.
4-Band Resistor Decoder
Live band rendering of your selection. FIG. E15-1
Capacitor 3-Digit Code
A truth table is a proof: two Boolean expressions are equal exactly when their columns match on all 2ⁿ rows. De Morgan's laws, absorption, consensus — every identity on the theorem sheet can be verified here mechanically.