Like a good painting, a computer port can long outlive its inventor — and few prove the point better than the 36-pin parallel port, a connector born in the casino industry that went on to define PC printing for decades.
Serial port on a laptop (Credits: How-To Geek)
The 36-Pin Parallel Port and the Casino Receipt Printer
The story starts with Centronics, a subsidiary of Wang Laboratories that primarily designed terminals for casinos. The company stumbled into a breakthrough after inventing a faster, more refined way to print casino receipts, and it spun that receipt-printer technology into the Centronics Model 101 — a machine that popularised both dot-matrix impact printing and the parallel interface.
Unlike serial ports, which stream data bit by bit and need extra hardware such as a buffer to work in a printing interface, the 36-pin parallel port could carry an entire byte across eight data lines simultaneously. The result was much faster printing — a genuine leap for offices of the era.
Why the Parallel Port Refuses to Die
Other printer manufacturers quickly adopted the 36-pin parallel port as a standard connector, and it became so deeply embedded in industry that it outlived just about everything that was supposed to replace it. Printers and office hardware have finally transitioned to USB, but the parallel port still lives on in plenty of legacy systems. Next time you are at the grocery store or gas station, take a look at the receipt printer — it might still use a parallel port.
The people behind it are gone: Centronics founder Robert Howard, who helped design the 36-pin parallel interface, passed away in 2014 at age 91, and co-developer Dr. An Wang died in 1990. The port, meanwhile, keeps working. It is a reminder that in computing, the most useful ideas are not always the newest — sometimes they are the ones too deeply embedded to ever fully disappear.
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Source: How-To Geek — read the full story there.
