9 Automated Design and Drafting Systems-Namely, Central Processing Units, Comprising Microcomputers, Disc Storage Units, and Magnetic Storage Units; Work Stations, Comprising Microcomputers, Visual Displays, Keyboards, Thumbwheel Cursor Controls, and Joystick Cursor Controls; Digitizers; Plotters; Hard Copy Apparatus; Input/Output Apparatus, Comprising Keyboards and Line Printers; Computer Software, Comprising General Computer System, Computer Operations Programs, Graphics Presentation Programs, Production Drafting Computer Programs, Engineering Design and Manufacturing Computer Programs, General Purpose Engineering Computing Programs, and Computer Programs Providing Access to Other Computer Systems