Talking dice - hear spots before your eyes

11-24 — elektor november 1982 talking dice talking dice C2 acts as a ripple filter. Potentiometer P2 adjusts the volume. The TMS 5100 contains an oscillator that provides the necessary clock pulses (160 kHz at pin 3 of IC1). Only three externa I components are required (R5, Cl and P1). The set- ting of P1 determines the clock fre- quency. The rest of the circuit consists of a con- trol interface ( IC2); the memory that contains the vocabulary (IC5); the address decoder/counter IC4; and finally the counter IC6 and the data selector (the actual number generator) IC7. Counting and initialisation As a result of depressing S2 a sequence starts, as shown in figure 2a. First 101 is initialised by pulses coming from IC2. IC2 is reset (line QO becomes logic 1). The pulse from S2 is inverted by T3 (logic 0) and fed to the CI input of IC6. This IC now "selects a random number" by counting the pulses supplied by the ROM/CLK output of IC1. Releasing S2 stops IC6, since the "carry in" input o...