 A third style of symbols, DIN 40700 (1976), was in use in Europe and is still widely used in European academia, see the logic table in .In the 1980s, schematics were the predominant method to design both circuit boards and custom ICs known as gate arrays.Today custom ICs and the field-programmable gate array are typically designed with Hardware Description Languages (HDL) such as Verilog or VHDL.