Some useful combinatorial modules 7400 – Quad 2-input NAND 7404 – Hex inverter 7420 – Dual 4-input NAND 7430 – 8-input NAND 74138 – 3-to-8 line decoder/demultiplexer 74151 – 8-line selector/multiplexer 74153 – Dual 4-input multiplexer Some useful sequential modules 7473 – Dual JK flip-flop 7474 – Dual D flip-flop 74273 – 8-bit register The twilight of MSI 4-bit Arithmetic Logic Unit Video about building a computer with the 74181 4-bit Bit Slice IEEE Standard Symbols for Digital Design: Principles and Practices by John Wakerly