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<p>joined. Digital logic as we know it was the invention of <a href="page.php?w=George_Boole">George Boole</a> in the mid-19th century. In an 1886 letter, <a href="page.php?w=Charles_Sanders_Peirce">Charles Sanders Peirce</a> described how logical operations could be carried out by electrical switching circuits. Eventually, <a href="page.php?w=vacuum_tube">vacuum tube</a>s replaced relays for logic operations. <a href="page.php?w=Lee_De_Forest">Lee De Forest</a>'s modification of the <a href="page.php?w=Fleming_valve">Fleming valve</a> in 1907 could</p><p>
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