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It’s a joke. The HP-67 was an engineer’s dream machine in its day, but that was in the late 1970s, when nobody could hope to own a personal computer. </p>
<p>Like other calculators of that era, it had a glowing red LED display, instead of black LCDs. You really could use it in the dark.</p>
<p>I expect you actually could still get through college with an HP-67 today, but given its value as a collectible, it wouldn’t make sense to let college students touch it.</p>