9 MULTIMEDIA PORTABLE INTERFACE SYSTEMS, COMPRISING AN EXPERT SYSTEM INTERFACE UNIT CONSISTING OF A COMPUTER, DIGITAL DISK, OPTICAL DISK PLAYER, PLASMA MONITOR, GRAPHICS GENERATOR BOARD AND A USER INTERFACE UNIT CONSISTING OF MICROCOMPUTER, PLASMA TEXT DISPLAY, PLASMA VIDEO DISPLAY, VOICE SYNTHESIS/VOICE RECOGNITION UNIT, SPECIAL KEYPAD, SMALL PRINTER AND HEADSET, FOR USE IN PROVIDING COMMUNICATION BETWEEN AN EXPERT SYSTEM AND AN END-USER TECHNICIAN