Few people have heard of it, yet many consider John Blankenbaker's KENBAK-1 to be the first commercial personal computer.

Koss introduced these headphones over 40 years ago, and they remain affordable favorites to this day.

The Floppy Drive That Changed The World

Disk-iiSometimes, seemingly small innovations have an enormous impact. A classic example is the nondescript Apple Disk II floppy drive. Its introduction propelled Apple II sales into the stratosphere.

Back in 1977, the Commodore PET, Radio Shack TRS-80 and Apple II led the first wave of the home computer revolution. Each machine used audio cassettes for program storage. While the Apple's 1500 bps transfer rate was fastest, it was also notoriously sensitive to minor level changes. Set your cassette deck's volume control too high or low, and the program load would mysteriously fail. This was a significant problem because, at $1298, the Apple II was more than twice as expensive as the others. It was the only machine to offer internal expansion and color graphics, but that alone wasn't quite enough to justify spending an extra $600 dollars on a fancy toy.

The finicky cassette interface drove Apple president Mike Markkula crazy. He grew tired of rewinding, fast-forwarding and countless minutes of boredom while waiting for software to load. And so, in a December 1977 executive meeting, he put "floppy disk" at the top of his wish list. It was a move that cemented Apple's position as a market leader for years to come.

Apple-ii-systemFloppy drives were complicated and expensive devices in 1977. They required large controller boards to encode the data and write it onto the disk in the appropriate place. Designing one for the Apple II was a formidable task.

Apple co-founder Steve Wozniak didn't have much experience with floppy drive controllers, but he had a few ideas he decided to try. His solution was revolutionary and relied heavily on software instead of an expensive board crammed with logic circuits.

A classic example of Woz's practical style is his approach to locating the first of the 35 concentric tracks on a disk. Traditional drives had a sensor that detected when the head reached track zero. Wozniak's software-only solution was to move the head 34 times, guaranteeing that it would reach the first track sooner or later, no matter where it was originally parked. It was the cheapest possible solution, although the repetitive mechanical clattering as the head bounced against the physical stop was disconcerting to new users. 

Apple-computer-logo Wozniak and Randy Wigginton (Apple employee #6) worked day and night over the Christmas 1977 vacation to design and build a working prototype, finishing just in time for the January 1978 Consumer Electronics Show in Las Vegas. The floppy controller plugged into slot six of the Apple II's built-in expansion area and was connected by a ribbon cable to a state-of-the-art Shugart 5.25" drive mechanism housed in an external case. Each single-sided floppy disk could hold 113.75 K (eventually increased to 140 K under DOS 3.3).

The Apple Disk II shipped in mid-1978 at $595, including the controller, a single drive and DOS 3.1. While that might seem an outrageous price for a floppy drive, it was dirt cheap by 1978 standards. And Wozniak's ingeniously simple design eventually cost Apple less than $100 to produce, generating massive profits. 

The availability of a speedy and affordable floppy drive made the machine incredibly attractive to business and home enthusiasts alike. Thanks to the Disk II, millions of users adopted the Apple II as their first "serious" computer, while the Commodore PET and TRS-80 Model I simply faded into history.

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