Physics — Logic: BCD invalid-code detector
Flags binary inputs above 9 (illegal BCD codes).
Make it your own.
title "BCD invalid-code detector"
type gates
input B3 at (0,0)
input B2 at (0,2)
input B1 at (0,4)
gate AND G1 at (3,1)
gate AND G2 at (3,3)
gate OR G3 at (6,2)
output Invalid at (9,2)
wire B3 G1
wire B2 G1
wire B3 G2
wire B1 G2
wire G1 G3
wire G2 G3
wire G3 Invalid