One breadboard's layout resembles this (there are two): ------------------ ------------------- ------------------ ------------------- | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------ ------------------- ------------------ ------------------- In V_OH, V_IH, V_OL, V_IL, - The O/I means it's the voltage output/input - The H/L means it's a voltage HI/LO (or 1/0) Max and min are the maximum and minimum acceptable voltage for that input/output for HI/LO. e.g. A gate's acceptable voltages may look like the following: +5V ||| max ||| ||| V_IH ||| ||| min | | | | | ||| max ||| V_IL ||| min =0V The 4-digit 7-segment multiplexed display has seven inputs: - D3 D2 D1 D0: the input for a single digit, from 0x0 to 0xF - A1 A0: the input for selecting a digit, where 0b11 is leftmost and 0b00 is rightmost - STR: when this voltage goes from LO to HI, the value given by Dx is loaded into the digit selected by Ax A brief circuit diagramme: Ohmm... +5V ----VVVV------------------------------------------------------------| | __ | __ | __ | __ | |_____| | |_____| | |_____| | |_____| | | ______|SW| ______|SW| ______|SW| ______|SW| |__ set manually | GRD-|__| | GRD-|__| | GRD-|__| | GRD-|__| | O| to select digit | | | | |__| | | | | | | | | | D3 D2 D1 D0 STR A1 A0 __ __ __ __ |__| |__| |__| |__| |__| |__| |__| |__| 11 10 01 00 == A1 A0