Abstract: An assembly board with a matrix of depending pegs uniformly spaced on orthogonal intersecting lines with pegs at intersections at half the distance adapted to selectively receive from a set, detachable and reusable electrical components housed in uniformly-shaped casings comprising at least 2 electrical connections uniformly spaced for interchangeability of components and stackable at the connections. Components with 2 connections are elongated with connection terminals at each end a standard distance apart. Components requiring a third connection are constructed in an equilateral triangular housing with a base having 2 terminals spaced apart the standard distance and a third connection half the standard distance from the base. Components having 4 or more connections are housed in a rectangular housing having terminals at corners with first opposing sides having terminals the standard distance apart at corners and the sides being spaced apart half the standard distance.