Index 8e4e2e1 binary system, 175e83 Accumulator register, 244, 245e6 ACER, 281e2 ACK and NAK codes, 219e20 Acorn, 282 Actions on pulses, 21e2, 205e21 Active components, 23, 26, 27, 42, 43, 47e59, 88, 169e83 see also Integrated circuits; Semiconductors; Transistors; Vacuum tubes definition, 23, 47 digital signals, 169e83 heat, 26, 52e3, 56e9, 169 noise concepts, 88 power, 23, 52e3 resistors, 55e6, 169 Active loudspeakers, 274e5 Adaptive threshold of hearing, AGP, 273 Altair, 59 Alternating current (AC), 12e14, 26, 29e32, 35e8, 43e4, 93, 111e12, 154 see also Hertz; Waveforms advantages, 13e14 coils, 35e7 DC conversion, 13e14, 38, 43e4 definition, 13 transformers, 37e8 uses, 13e14 Alternating voltage, concepts, 10e14 Alternators, concepts, 13e14, 77, 99e100 ALU see Arithmetic and logic unit AM see Amplitude modulation Amber rubbed with silk, static gain concepts, 67e74, 87e8, 109 tuned amplifiers, 71e4, 78, 106e12 Amplitude modulation (AM), 101e12, 114, 144e5, 158e65, 175, 266e70, 302 critique, 103e4, 107, 109 definition, 101 historical background, 101e12 Amplitude shift keying (ASK), 266e70 Amplitude of the waves, 16e17, 19e20, 27e8, 31, 61e78, 144e5, 266e70 see also Peak. definition, 16e17, 19, 61e3 Amps, 5e10, 14e15, 24e8,