ted in conjunction with the accompanying drawings, in which: FIG. 1 is a schematic drawing of a well-known Eccles- Iordan flip-flop circuit; FIG. 2 is a schematic drawing of a direct-coupled transistor logic flip-flop; FIG. 3 illustrates the operation of a direct-coupled amplifying stage of the type employed in the invention; FIG. 4 is a schematic representation of an embodiment of the invention;