The ACM Computing Classification System (1991) B.0 GENERAL B.1 CONTROL STRUCTURES AND MICROPROGRAMMING (D.3.2) B.2 ARITHMETIC AND LOGIC STRUCTURES B.3 MEMORY STRUCTURES B.4 INPUT/OUTPUT AND DATA COMMUNICATIONS B.5 REGISTER-TRANSFER-LEVEL IMPLEMENTATION B.6 LOGIC DESIGN B.7 INTEGRATED CIRCUITS B.m MISCELLANEOUS