“With its professional-looking (for 1977) injection-molded case and a design aesthetic to match Jobs’ perfectionism, the Apple II was a breakthrough product for the time. But though it was years ahead of the kit-like Apple I that it was meant to replace, the Apple II still only offered a cassette drive,” Daniel Terdiman reports for CNET. “Wozniak and Jobs weren’t blind to the need for a functional, and powerful, disk drive and a disk operating system to run the system.”
“Talk to just about anyone intimately familiar with the Apple II, and one thing you’ll hear often is that the disk controller Wozniak designed over the 1977 Christmas holidays for the computer was a proverbial game changer. The chief innovation was making the controller compact by using software while competitors relied on hardware. As Bill Fernandez, then an electronic technician at Apple, remembers it, ‘the key advantage of [Wozniak’s] design [was] that it used only six chips instead of the usual 60 to 70 — a huge reduction in size and cost,'” Terdiman reports. “Dan Bricklin, the co-creator of VisiCalc, said Woz’s controller was ‘wonderful,’ while Lee Felsenstein, the creator of the Osborne I, marveled at its ‘elegance.’ Bruce Damer, founder of the DigiBarn, called it ‘masterful.'”
Terdiman reports, “But no matter how great its disk controller was, Apple had no DOS. Or any way to build one of its own… Although he knew little about operating systems, Wozniak is confident he could have built a good one. But his co-founder couldn’t wait. ‘”Steve Jobs, who didn’t have patience for a project that took more than a week, found [Shepardson Microsystems] and…they sounded eager and knowledgeable…so we hired them.’ As then-Shepardson employee Paul Laughton remembers it, Wozniak came by one day saying Apple had a disk drive, but no DOS, and was wondering what to do. ‘I said, ‘I know about operating systems.’ And so he said, ‘Cool, let’s have you do it.” On April 10, 1978, the contract was signed. For $13,000 — $5,200 up front, and $7,800 on delivery, and no additional royalties — Shepardson Microsystems would build Apple’s first DOS.”
Tons more in the full article – recommended – here.