PLDT-1 Trainer

TTL clock signal from a function generator can be brought onto the board via jack labeled “EXT CLK IN” on the T7 pin-jacks (detail 7). CLK IN is buffered by a 74HC00 and the buffered clock is available on the T8 pin-jacks. 4.4.2 The Low-Frequency Clock. An on-board clock of approximately 1 Hertz is available at pin-jacks on T9 (see detail 6). ................
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